For the third time in the last four games, USC blew a fourth quarter lead in agonizing fashion as its season endured yet another stinging setback Saturday -- this time a 33-30 overtime loss to No. 4-ranked Penn State that coach Lincoln Riley called a "gut punch."

"Just a really difficult loss. There's really no way to sugarcoat that," he said.

No, there sure isn't.

The Trojans entered the second half up 14 points with a prime opportunity to give fresh life to their season goals, vault back into the rankings and national conversation and rebound emphatically from the deflating collapse last week at Minnesota.

Instead, the outcomes just get more excruciating with each dramatic defeat.

That two-touchdown lead was gone before the end of the third quarter, but that wasn't the worst part. The Trojans scored another go-ahead touchdown with 5:56 left in the fourth quarter, only to allow the Nittany Lions to convert on fourth-and-7 and fourth-and-10 on a game-tying touchdown drive capped by the easiest 14-yard touchdown pass imaginable as running back Nicholas Singleton was inexplicably left entirely alone on the right side of the field.

But still, it got worse from there.

USC (3-3, 1-3 Big Ten) had 2:53 left on the clock to drive for the win, but the Trojans got only as far as the Penn State 45-yard line before Miller Moss sailed a third-down pass beyond the reach of an open Duce Robinson for an interception to force overtime.

The pain was still mounting for Trojans fans ...

USC got the ball first in overtime, ran three unsuccessful plays and Michael Lantz -- who had hit on all three of his field goal attempts Saturday to that point -- missed wide left on a 45-yarder, clearing the way for Penn State (6-0, 3-0) to chip in a 36-yard game-winning Ryan Barker field goal.

RELATED: Watch the postgame press conference with Lincoln Riley and players

Change any of those moments -- the two fourth-down conversions allowed, Moss missing a wide-open Robinson on a pass that should have set up a game-winning field goal try with no time left, Lantz missing in overtime -- and others and USC's season looks entirely different.

But that's the thing ... this keeps happening.

The defensive bust on Michigan's game-winning touchdown drive after having stopped the Wolverines the six prior series. The protection breakdown leading to the interception in Minnesota territory that gave a limited Gophers offense the momentum to score touchdowns on its next two drives to steal the win. And now this.

"It's the good and bad of it, and it both exists," Riley said. "The reality is we've played the toughest schedule in the country the first six games, we've had a chance to win every single game. That's hard to do, to put yourself in position to win these games is frickin' hard to do to begin with, so we're doing a lot of good. And I understand that that good's not going to get seen by the outside right now because they're going to focus on the record and the fact that we've lost three games on the last play, and I understand it.

"That's part of it. We all understood this when we signed up for big boy football, so I get it. We've got to do a better job at the end of games, I have to do a better job, our coaches, our players, because we're doing too many good things to put us in situations where we have the lead and we can win, but we gotta get paid off for it. We gotta be able to finish, and it all falls on my shoulders at the end."

Unlike last week when he said multiple times that his team was two plays away from being 5-0, Riley didn't go back to the well with that one.

But one can certainly wonder what USC's season could have been.

What it is instead is a season where the biggest goals -- Big Ten championship, College Football Playoff berth -- are now off the table.

"Shoot, they all hurt. This one especially was excruciating just in the manner that it happened," Moss said. "I think the flip side of that is we've got a really, really good locker room filled with really great people and really great coaches that's going to continue to stay together and go on a run this back half of the season. That's the No. 4 team in the country, so what does that make us?"

A team with a lot of "what-ifs" now sitting near the bottom of the Big Ten standings.

As noted, though, it sure looked like Saturday was going to be a much different story.

Moss finished 20-of-34 passing for 220 yards, 2 touchdowns and 1 interception in what was objectively his worst performance of the season, as he missed several receivers through the day capped by the overthrow to Robinson on that final drive of regulation.

But the USC run game was again successful, as Woody Marks (20 carries for 111 yards) and Quinten Joyner (3 carries for 82 yards and TD) combined for 193 rushing yards on 8.4 yards per carry.

They helped stake the Trojans to a quick 14-3 lead as Joyner ripped off a 75-yard touchdown on a fake reverse in the first quarter and then scored on a 9-yard touchdown reception early in the second quarter, set up by back-to-back runs of 21 and 28 yards by Marks.

An interception by freshman linebacker Desman Stephens II, seeing his most significant action yet, led to 45-yard Lantz field goal. And Lantz would hit again from 47 yards near the end of the half to stake USC to a 20-6 lead.

But then it all started to unravel -- due in large part because the Trojans had no answer for Penn State tight end Tyler Warren, who would finish with 17 catches for 224 yards and a touchdown. The 17 catches is a record for any opposing player against USC all-time.

"We knew he was going to be a challenge coming in. We had a couple coverage busts on him, and I think that's the thing we'll look back on," Riley said. "When you play a really good player like that, you just want to make him earn it, right? If they make a play, you want it to be like, hey, we were in coverage, we were in the right spot, listen, the guy made a play. But we gave him a couple that we didn't [play well] and that's probably the thing that hurts the most."

Warren hurt USC over and over again, including a 32-yard touchdown over safety Zion Branch to open the third quarter (on a play that started with him snapping the ball to quarterback Drew Allar).

A holding penalty on Marks then wiped out a 42-yard completion from Moss to Robinson down to the Penn State 4, and USC instead eventually punted.

With that, the Nittany Lions continued to build on their momentum with another touchdown drive -- including a 34-yard completion to Warren -- capped by Kaytron Allen's 1-yard scoring run to tie the game at 20-20 in the third quarter.

USC's defense bounced back to force an interception on its next turn as Kamari Ramsey got a hand on the ball and linebacker Easton Mascarenas-Arnold corralled it out of the air, setting up another Lantz field goal (from 39 yards) for a 23-20 lead late in the third quarter.

And the Trojans later went back ahead 30-23 with 5:56 left in the fourth quarter on a 9-play, 75-yard drive as Moss navigated pressure in the pocket to find Robinson for 25 yards on third-and-6 and then hit Kyron Hudson for a 5-yard touchdown.

It was all just a precursor to another letdown, however.

On the ensuing game-tying Penn State touchdown drive, Allar threw a 17-yard pass to Julian Fleming on fourth-and-7 near midfield, and then with the game essentially on the line he found Fleming again for 16 yards on fourth-and-10 -- both times beating cornerback John Humphrey, who had a rough game.

The disappointment was punctuated when Singleton slipped out into the right flat with no USC defenders noticing him, allowing him to waltz in for an easy touchdown.

Many fans then took issue with Riley's clock management as USC got the ball back with 2:53 to work with and all three timeouts and chose to let the clock run down in hopes of kicking a game-winning field goal.

Riley explained that he made that decision after USC lost yardage to set up a second-and-12 inside the final minute.

"We were talking about it, do we need to use timeouts and stop the clock there because all of sudden it's second-and-12. If you don't get anything there then it's third-and-12 and you just potentially bought them a series and we weren't in field goal range yet. We went back and forth on do we use them and stop the clock, or not? Honestly, I felt so good about how Mike was hitting the ball that we said, 'You, know what' -- when we got to a third-and-6 there -- 'if we convert this we still got timeouts to maybe go one more shot and then obviously let him kick the field goal.' How well Mike was kicking it, I think, was the biggest reason I wanted to make sure it was the last possession," Riley said.

And if Moss hits Robinson who was open coming across the middle with room to run after the catch, then it would have been a sound strategy. But he did not, leading to the overtime heartbreak and another tough outcome to digest.

Riley was asked which moment in particular will stick with and frustrate him the most ...

"Man, we do this for a living, like this is our life. I didn't see my kids four nights this week. This is what we do. I think about this every second, and when I go to sleep I dream of it and I wake up thinking about it. So, I'll think about all of it," he said. "The thing I'm not going to do, and our team's not going to do, is I'm not going to let the things we have to get better or the things that didn't go our way shield the great things that are happening in that locker room, on this defense, on this offense and in this program.

"I am not going to let that happen, personally, because I've been in this long enough, man -- everybody's going to hit their adversity, that's part of it, and you either stand up and fight or you bow down. And I'm not about to bow down."

The top-end goals are off the table, but sure, there's plenty left to play for -- like not finishing near the bottom of the conference in USC's Big Ten debut season, salvaging a decent record, building positive momentum for the trajectory of the program, etc.

But that's not where anyone expected the bar to be set at by the midway point of this season.

USC needed to win Saturday to avoid that reality -- and it sure had every chance to do so.

"We've got a united bunch of guys in that room that are hurting right now because they love playing the game with each other. I think you can tell that. They love playing the game for each other, for USC. That's why you see us play the way that we play. So, they're hurt, but we will absolutely rebound," Riley said.

"We're excited about what's coming up and we understand the opportunities that are ahead for us. And we will be a hungry motivated football team to go back to work and obviously dive into the second half of this season."

First quarter

4:53, PSU -- Ryan Barker 34-yard field goal, PSU 3-0

4:38, USC -- Quinten Joyner 75-yard run (Michael Lantz kick), USC 7-3

Second quarter

13:33, USC -- Quinten Joyner 9-yard pass from Miller Moss (Michael Lantz kick), USC 14-3

10:05, USC -- Michael Lantz 45-yard field goal, USC 17-3

2:46, PSU -- Ryan Barker 33-yard field goal, USC 17-6

:07, USC -- Michael Lantz 47-yard field goal, USC 20-6

Third quarter

12:52, PSU -- Tyler Warren 32-yard pass from Drew Allar (Ryan Barker kick), USC 20-13

4:42, PSU -- Kaytron Allen 1-yard run (Ryan Barker kick), USC 20-20

:28, USC -- Michael Lantz 39-yard field goal, USC 23-20

Fourth quarter

10:50, PSU -- Ryan Barker 20-yard field goals, USC 23-23

5:56, USC -- Kyron Hudson 5-yard pass from Miller Moss (Michael Lantz kick), USC 30-23

2:53, PSU -- Nicholas Singleton 14-yard pass from Drew Allar (Ryan Barker kick), 30-30

Overtime

0:00, PSU -- Ryan Barker 36-yard field goal, PSU 33-30

Passing

Miller Moss: 20 of 34 for 220 yards, 2 TDs, 1 INT

Rushing

Woody Marks: 20 carries for 118 yards

Quinten Joyner: 3 carries for 82 yards, TD

Miller Moss: 1 carry for -4 yards

Receiving

Makai Lemon: 6 catches for 73 yards

Kyron Hudson: 4 catches for 36 yards

Woody Marks: 2 catches for 44 yards

Ja'Kobi Lane: 2 catches for 18 yards

Quinten Joyner: 2 catches for 12 yards

Zachariah Branch: 2 catches for 6 yards

Duce Robinson: 1 catch for 25 yards

Jay Fair: 1 catch for 6 yards

Defense

Easton Mascarenas-Arnold: 13 tackles, 1 INT

Kamari Ramsey: 10 tackles, 2 PBUs, 0.5 TFL

-With 111 yards, Woody Marks notched his fourth 100-yard rushing game in six tries this season after having only two career 100-yard rushing games in four seasons at Mississippi State. With 579 rushing yards this season, he is just 3 short of matching his career-high from 2022.

-Marks extended his streak of consecutive games with a catch for 51, which is the longest active streak in college football.

-Quinten Joyner's 75-yard touchdown run was the longest by a Trojans since Ronald Jones II had an 86-yard touchdown run at Washington State in 2017.

-Wide receiver Duce Robinson, wearing No. 52 while playing on defense for one snap to guard against a Penn State Hail Mary at the end of regulation, made an interception.

-Penn State TE Tyler Warren set the USC opponent record for receptions in a game with 17 (breaking Utah TE Dalton Kincaid's previous record of 16 in 2022). Warren's 224 receiving yards is the fourth-most ever against USC.