Back in the BCS business

As USC began the most challenging stretch of its schedule, Coach Pete Carroll implored his team to keep its focus on the immediate task at hand.

A Bowl Championship Series title-game appearance or a Rose Bowl berth were within reach, but they were to remain distant goals.

On Saturday night, after several other one-loss teams perhaps got caught looking ahead, seventh-ranked USC took a major step toward its coveted rewards by defeating No. 21 Oregon, 35-10, before a homecoming crowd of 92,000 at the Coliseum.

Tailback Chauncey Washington rushed for a career-high 119 yards and three touchdowns in 15 carries and USC took advantage of two Oregon turnovers en route to its 31st consecutive home victory.

On a day when the BCS dominoes continued to topple, USC improved its record to 8-1 overall and 6-1 in the Pacific 10 Conference and remained in control of its postseason destiny.

The Trojans entered the game seventh in the BCS standings but are expected to vault to fourth today, behind No. 1 Ohio State, Michigan and Florida. Notre Dame is expected to be fifth.

The BCS shuffle started when previously unbeaten Louisville lost on Thursday to Rutgers. On Saturday, Texas and Auburn suffered their second losses and Florida barely held on to defeat South Carolina.

The Trojans won’t know their BCS standing until this evening but they left the Coliseum with a share of first place in the Pac-10 because Arizona upset eighth-ranked California.

Cal visits the Coliseum this Saturday and ninth-ranked Notre Dame follows before the season finale at the Rose Bowl against UCLA.

“It puts us in tremendous position here in the second round of the ‘playoffs,’ ” Carroll said. “That’s what it feels like to me, with four games and home-field advantage.”

Two weeks ago, the Trojans’ hopes for a third consecutive BCS title-game berth appeared to end when an Oregon State defensive lineman batted away a two-point conversion pass in the final seconds, leaving USC with a 33-31 defeat.

But the Trojans rebounded with a 42-0 win over Stanford and kept the momentum going against Oregon.

“It really doesn’t change much,” offensive tackle Sam Baker said of the victory and its impact on USC’s BCS chances. “We still have to win out. That’s the only thing we can control now.”

The Trojans did a good job of controlling the freewheeling spread offense of Oregon, which Carroll had described last week as a “wide-open, can-break-your-heart team.”

The Ducks, led by quarterback Dennis Dixon and running back Jonathan Stewart, came into the game averaging a conference-best 36.3 points a game, but with a propensity for committing turnovers in big games on the road.

USC took full advantage.

Freshman safety Taylor Mays intercepted a pass in the second quarter that led to Washington’s five-yard touchdown run and a 14-0 lead. Linebacker Dallas Sartz recovered a third-quarter fumble that led to Washington’s three-yard touchdown and a 21-3 lead.

Washington also scored on a 43-yard dash to the end zone that put the Trojans ahead, 28-3, at the end of the third quarter.

Oregon (7-3, 4-3 in the Pac-10) pulled to within 28-10 on a touchdown pass from Brady Leaf to Stewart early in the third quarter, but USC answered with a 12-yard touchdown pass from John David Booty to Dwayne Jarrett.

“They’re SC, they have a bunch of talented players, and the talent kind of showed tonight,” said Oregon linebacker Blair Phillips, who had a first-quarter interception, USC’s only turnover. “But we made it easy for them with penalties and mistakes.”

Booty completed 16 of 25 passes for 176 yards and one touchdown. Jarrett had six receptions for 54 yards, Steve Smith seven catches for 87 yards.

USC failed to capitalize on an early opportunity but managed to build a 14-0 halftime lead by scoring twice in less than two minutes early in the second quarter.

Oregon, which came in averaging a conference-best 457 yards of offense, looked the part for most of the first possession.

Starting at the Oregon 15, Dixon led a 14-play march to the USC 14. But after Dixon threw an incomplete pass, linebackers Oscar Lua and Kaluka Maiava stopped Dixon short on a third-and-two play. Oregon went for it on fourth down and Maiava and Lua stuffed Dixon for no gain, ending a drive that consumed more than eight minutes.

USC appeared poised to capitalize when Jarrett turned a short swing pass into a 37-yard gain down the left sideline. But six plays later, USC gave the ball back when Phillips leaped, tipped and then intercepted Booty’s pass, intended for Smith in the end zone.

USC got the ball back with about three minutes left in the first quarter and finally got on the scoreboard. Booty completed three passes to Smith during an 80-yard, 12-play drive that C.J. Gable capped with a two-yard touchdown run for a 7-0 lead with 12:22 left in the second quarter.

The Trojans defense wasted no time getting the ball back. On the first play of the ensuing drive, Dixon dropped back from the 20 and looked for Jaison Williams near the right sideline. With cornerback Cary Harris shadowing Williams, Mays launched himself into the air at the 42 and grabbed the ball for his second career interception.

The 6-4, 225-pound freshman then rambled across the field to the seven. Two plays later, Washington bulled his way into the end zone for a 14-0 lead.

Oregon looked as if it might avoid a first-half shutout on the final possession of the half, driving from its 38 to the USC seven. Running back Jeremiah Johnson caught Dixon’s third-down pass in the back of the end zone but he was ruled out of bounds.

Paul Martinez then missed a 23-yard field-goal attempt, preserving USC’s 14-point lead.

The Trojans now head into the home stretch of the regular season, Saturday’s string of upsets having given them a suddenly improved BCS outlook.

Said defensive end Lawrence Jackson, who had his first sacks of the season: “It’s not like we don’t see that stuff, or we don’t care about it. We just have to stay focused.”

gary.klein@latimes.com