This USC basketball season will not be remembered with any nostalgia. The Trojans underachieved from start to finish and never found a way to maximize the sum of their considerable talent.

That said, their last stand Thursday was spirited and entertaining, and right until the end of this Pac-12 Tournament quarterfinal matchup there was lingering hope that they just might stun top-seeded Washington and make a run after all.

But the first of two costly turnovers in the final minute helped the Huskies stretch out their lead and the Trojans' last gasp was ultimately felled by an errant pass out of bounds that prevented a look at a potential game-tying 3-pointer.

Washington survived for the 78-75 win while dealing USC one last deflating finish.

"This is a microcosm of our whole season, the last 3 minutes because we've been in so many close games and we've made some crucial mistakes with turnovers, missed free throws, missed shots, not getting stops. And we've been right there," Trojans coach Andy Enfield said.

Again, though, the Trojans played until the end and made the finale of a lost season rather compelling (assuming the team isn't invited to a tertiary postseason tournament).

While it had missed opportunities throughout the game, the moments that USC (16-17) will lament the most came in the final minute.

It was a six-point deficit when Bennie Boatwright pump faked and drained a 3-pointer near the top of the key to cut it to 71-68 with 1:47 to play. After Pac-12 Player of the Year Jaylen Nowell made one of two free throws at the other end, Jonah Mathews knocked down a long 3 from the right side on a nice kickout from Nick Rakocevic to make it a 72-71 game with a little more than a minute to go.

That's when the comeback fell apart -- twice.

Dominic Green followed with a clutch 3 at the end of the shot clock for Washington (25-7), and Huskies defensive stalwart Matisse Thybulle followed with a steal off a lazy pass by Derryck Thornton that he converted into a fastbreak windmill dunk and a 77-71 lead with 32 seconds to play.

Still, the Trojans would have one more opportunity to steal this game.

Thornton got fouled on a 3-point attempt and made two of three free throws, Washington's Noah Dickerson missed the front end of a one-and-one and Rakocevic tipped in a short Boatwright miss to cut the deficit to 77-75.

USC then immediately fouled Nowell with 7.9 seconds left. He made the first and missed the second, making it a three-point game.

Rakocevic, the 6-foot-11 junior, grabbed the rebound and decided to bring the ball upcourt himself. With Washington closing in to try to foul him, he elevated and tried to force a pass to Shaqquan Aaron on the right side, but he threw it out of bounds instead.

Perhaps, like Enfield noted, it was a fitting end for a season that went awry far too often.

"That's called the 5-man special. We want our worst ball-handler and slowest guy handling the ball and throwing it out of bounds. We called that play in a timeout about 8 minutes before," Enfield said with dry sarcasm

Enfield has been especially hard on Rakocevic, his second-best player, all season for mental lapses, usually in the way of losing control of his emotions on bad fouls or technicals.

Despite the costly final turnover, though, Rakocevic led USC with 17 points and 17 rebounds. Mathews also scored 17 points and freshman Kevin Porter Jr. had a career-high 17 points and 6 rebounds in what is expected to be his last game with the program as a projected first-round NBA Draft pick.

"Kevin's improved. He played hard tonight and helped us. I thought he played a terrific basketball game on both sides of the ball," Enfield said.

Boatwright, who delivered one big 3 after another down the stretch, had 16 points, 7 rebounds and a career-best 7 assists. With 4 more 3s Thursday, he finishes second in program history in 3-pointers with 243 trailing only former teammate Elijah Stewart's 245.

As he so often has this season, Boatwright delivered in big moments Thursday while helping set up that late rally.

USC was down by as many as 12 points late in the first half, but Boatwright stopped that slide with a 3 and the Trojans closed to within 43-38 at halftime (after Porter banked in a long 3 at the buzzer).

USC was then down 10 midway through the second half when Boatwright knocked down a 3. After Nowell hit one to push it back to a 10-point lead, Boatwright eventually struck yet again from the outside to spark the Trojans' late surge.

One that sustained right up until those final seconds and that last costly turnover.

"Washington played very hard. As did our team. We obviously made a few mistakes in the last two and a half, three minutes like we have many times this season. So it's unfortunate that we weren't able to win, but I'm very proud of our players -- especially our seniors Shaqquan Aaron, Bennie Boatwright," Enfield said. "Bennie had just a terrific career, Shaqquan's meant a lot to our program. Both have won a lot of games the last few years. Again, give Washington credit. They earned the win -- they played for 40 minutes."

Nowell led Washington with 24 points and 8 rebounds. David Crisp had 18 points and 6 assists, and Thybulle was held to just 4 points but he had 5 steals while breaking the Pac-12 single-season record in that category (now 115).

USC finishes with its worst record since Enfield's second season with the program in 2014-15. It's his third losing season in six years at the helm.

"When you're in these close games every possession matters, so I guess to answer your question, the last couple minutes was a microcosm of our season," Enfield reiterated. "We're good enough and talented enough to compete, our players play hard, but our margin of error is so small that those crucial moments, whether it's a turnover, defensive stop, made shot, a free throw or a last-second shot haven't gone our way this year.

"It's been unfortunate, but our players, I'm very proud of them, especially our upperclassmen who played exceptionally hard all season."