One team is surging, the other trying to regain its balance after embarrassing losses and weeks of public flogging.
But for the first time in years the roles are reversed.
When USC and UCLA play for the 79th time tonight at the Coliseum, Coach Pete Carroll and his recently staggering Trojans will try to hold off a Bruins team eager to show that the school's infamous "monopoly" marketing campaign was no joke.
"This is a different chapter for UCLA football and a different chapter for USC football," Bruins Coach Rick Neuheisel said.
UCLA hopes to make it a storybook finish.
The Bruins have not won at the Coliseum since 1997, UCLA's second-to-last victory during an eight-game winning streak against the Trojans.
For the last 10 years, the crosstown rivalry has belonged to USC. The Trojans' only stumble came three years ago when the Bruins knocked them out of the Bowl Championship Series title game with an upset at the Rose Bowl.
The immediate stakes are not nearly as high tonight.
After a humiliating 55-21 defeat by Stanford at the Coliseum two weeks ago, USC is ranked 24th, its lowest position in the Associated Press poll since being unranked at the end of the 2001 season.
The Trojans are 7-3 overall and 4-3 in the Pacific 10 Conference. The Rose Bowl is off the table, so representatives from the Holiday, Emerald and Poinsettia bowls will be attendance tonight to monitor the Trojans.
New Mexico and Humanitarian bowl officials also will be on hand. The Bruins are bowl eligible after pulling out of a five-game skid by winning three consecutive games to improve to 6-5, 3-5 in Pac-10 play.
"They're feeling great about themselves," Carroll said. "And deservedly so."
USC's mind-set is not so clear.
The confidence and swagger earned with early-season road victories at Ohio State and California are gone, wiped out by blowout losses at Oregon and against Stanford.
The defense, in particular, has been lambasted after the Trojans gave up a combined 102 points and 1,082 yards in the two defeats.
Oregon and Stanford both found plenty of running room, combining for 716 yards rushing. However, UCLA has had trouble running all season. The Bruins' average of 114.8 yards rushing a game is next-to-last in the Pac-10.
"We understand the situation we're in," middle linebacker Chris Galippo said. "We take it as it comes and use it as motivation or whatever it is, but I think that we're ready to rebound and come out with a win."
Another key for both teams will be the play of their young quarterbacks.
USC's Matt Barkley, a true freshman, became the talk of college football by going unbeaten in his first six starts.
But Barkley has struggled in most of the last three games.
He was ineffective in the second half at Oregon, was saved by Damian Williams' 75-yard catch-and-run touchdown against Arizona State, and had four turnovers against Stanford.
Nevertheless, Carroll and quarterbacks coach Jeremy Bates remained steadfast in their support, refusing to even consider giving sophomore Aaron Corp and junior Mitch Mustain a chance to compete for the starting job.
Barkley should be buoyed by the return of Williams, his top receiver who did not play against Stanford because of an ankle injury. Tight end Anthony McCoy and fullback Stanley Havili also are closer to full strength, giving Barkley a full complement of weapons against a Bruins defense that leads the conference in tackles for losses and interceptions.
While Barkley has known nothing but over-the-top support from his coaches, UCLA quarterback Kevin Prince has weathered different treatment from Neuheisel.
Prince, a redshirt freshman, was under center for the Bruins' 19-15 victory at Tennessee. But with that win all but wrapped up, Neuheisel sent Prince on a naked bootleg in the UCLA end zone and the quarterback was leveled.
Prince suffered a fractured jaw and missed the next two games. He struggled when he returned, suffering through criticism from Neuheisel about consistency. Twice after losses, Neuheisel said he wanted to "review" the quarterback situation and give freshman Richard Brehaut an opportunity.
But Prince hung on to his starting spot and showed he deserved it in the fourth quarter Oct. 31 against Oregon State, completing nine of 13 passes for 198 yards and two touchdowns, though the Bruins lost, 26-19.
"He's been very effective and been a big factor for them throwing the football and moving enough to get the wins that they've been getting," Carroll said.
For Neuheisel, no win would be bigger than one over USC. A victory would send a signal, especially to potential recruits, that the Bruins have leveled the playing field with the Trojans.
"We have the knowledge things are possible, that's definitely important," Neuheisel said. "We do not feel superhuman efforts are required to get things accomplished."
gary.klein@latimes.com
twitter.com/latimesklein
Times staff writer Chris Foster contributed to this report.
