The No. 6-ranked Trojans battled through a tough slog of a game with Washington State on Saturday night before scoring the final 20 points to close out a 30-14 victory.

After a tight first half, USC held the Cougars scoreless through the second as the defense and rushing offense powered the team to a win.

The Trojans (6-0, 4-0 Pac-12) move to 6-0 for the first time since 2006.

"It means something, it does. When you're in the middle of it, you try not to get too caught up in all the historical things, but obviously all of us coming here ... we all came here for a reason," coach Lincoln Riley said. "We're all aware of the history, both positive and some of the tough parts of it. To be able to find a way to win these games, especially in a lot of different ways has been a lot of fun. But we know obviously more challenges are upcoming. We're going to appreciate it but also keep our sights forward."

RELATED: Watch the postgame press conference with Lincoln Riley, Travis Dye and Tuli Tuipulotu | Watch more postgame interviews with USC players

First quarter

8:31, USC, Mario Williams 38-yard TD pass from Caleb Williams (Denis Lynch kick), USC 7-0

3:32, USC, Denis Lynch 31-yard field goal, USC 10-0

Second quarter

14:56, WSU, Robert Ferrel 12-yard TD pass from Cam Ward (D. Janikowski kick), USC 10-7

11:48, WSU, Nakia Watson 1-yard TD pass from Cam Ward (D. Janikowski kick), WSU 14-10

2:10, USC Travis Dye 4-yard TD run (Denis Lynch kick), USC 17-14

Third quarter

5:17, USC, Mario Williams 24-yard TD pass from Caleb Williams (Denis Lynch kick), USC 24-14

Fourth quarter

9:09, USC, Denis Lynch 27-yard field goal, USC 27-14

2:08, USC, Denis Lynch 31-yard field goal, USC 30-14

The game was in a rut as the third quarter dragged on, and the Trojans continued to find themselves unable to move the ball while the Cougars continued to keep threatening. After a promising drive, Washington State's offense found itself with a fourth-and-9 on the USC 38. Trailing 17-14, the Cougars decided to swing big and go for it. QB Cam Ward dropped back to throw but found nobody, forced to roll out of the pocket as the pressure reached him. He threw the ball grasping for a play and it went incomplete, giving the Trojans a critical stop to retain the lead.

USC finally managed to score a touchdown on the following drive -- aided by 25 yards worth of WSU penalties and capped by a 24-yard Caleb Williams to Mario Williams TD pass -- at last securing a comfortable lead that would last the rest of the way. (More on that sequence below ...)

As the midpoint of the third quarter loomed, USC's offense looked stumped, as drive after drive passed without a touchdown scored. The Cougars hung around down 17-14 as they had since halftime, but that big fourth-down stop gave USC the ball back with a chance to stretch its lead. After a drive peppered with miscues and penalties, the Trojans found themselves once again with an inopportune situation, faced with a third-and-13 at the Washington State 24-yard line. As they lined up for the snap, Caleb Williams' cadence caught a man offsides, giving the Trojans a free play. Williams scanned deep and launched it to the middle of the end zone, where it was hauled in by a sliding Mario Williams for a high-difficulty touchdown grab. Williams had dropped a wide-open pass earlier in the drive, but made up for it to extend USC's lead.

RB Travis Dye

As has been the case whenever Caleb Williams and the passing offense has slowed down, Travis Dye stepped up big to help keep the Trojans moving. Dye created sizable gains for USC with reliability, averaging 5.3 yards per carry through the contest. His patience and vision allowed him to get the most out of his blocking consistently, keeping USC’s offense on schedule even when the passing attack was struggling. Dye scored a short first half touchdown and came up big in the fourth quarter, seemingly carrying the entire offense through the final phase of the game. He was handed the football 13 times in that quarter for 68 yards, adding another 10 yards on a reception, powering the team through to the finish.

Overall, he carried it a season-high 28 times for 149 yards and added 18 receiving yards.

DL Tuli Tuipulotu

Tuli Tuipulotu was a man on a mission in this game, causing nightmares for the Washington State offensive line right from the jump. Screaming off the edge, Tuipulotu sacked QB Cam Ward twice on the Cougars' second possession to force a quick punt. He made another big tackle for loss later in the quarter as he continued to create penetration consistently from down to down. Tuipulotu came up big once again late in the second quarter, sacking Ward on third-and-3 to stymy another drive as he secured his third sack of the night before halftime.

He continued to generate pressures on Ward through the third quarter, getting home once again on third-and-23, though Nick Figueroa was credited with the sack.

His persistent presence in the backfield created havoc for the Cougars offense and played a big role in their lack of scoring.

Tuipulotu now leads the country with 7 sacks through 6 games and already has 12.5 tackles for loss.

The passing offense wasn't at its best tonight, but the rushing attack came to play. Dye and the Trojans offensive line made sure that the ball kept moving on the ground, powering through with a big fourth quarter in the run game to seal the win. USC's defense played well for most of the game as well, coming up with 5 sacks despite Cam Ward's incredible escapability. The Cougars were held to only 14 points despite plenty of moments when they seemed to threaten, as the defense found ways to stiffen on late downs and near the red zone. Special teams was also at its best for USC this game, as the group fared much better on return and coverage units than they have throughout the year.

The Trojans are still a flawed team with questions to answer, but they've shown the ability to grind out tougher games in the second half. Though it may not have been very pretty, the Trojans went from a 17-14 halftime lead to a 30-14 victory, holding the Cougars scoreless in the second half. The defense has a lot of positive signs to feel good about, as does the rushing offense. However, the passing offense once again had issues crop up, and those will need to be straightened out if USC wants to compete at the level it wants down the stretch. Next week's test against Utah at Rice-Eccles Stadium will be as tough as any this season.

Passing

Caleb Williams: 15/29, 188 yards, 2 TD

Rushing

Travis Dye: 28 carries, 149 yards, 1 TD

Caleb Williams: 9 carries, 34 yards

Raleek Brown: 2 carries, 5 yards

Jordan Addison: 1 carry, -7 yards

Receiving

Mario Williams: 4 receptions, 82 yards, 2 TD

Brenden Rice: 3 receptions, 38 yards

Jordan Addison: 3 receptions, 37 yards

Travis Dye: 3 receptions for 18 yards

Raleek Brown: 1 reception for 9 yards

Lake McRee: 1 reception for 4 yards