Having lost two straight and playing without one of its leaders, Southern California was feeling a good bit of pressure.

A lousy first half just added to it.

But with freshman star O.J. Mayo and backup forward Keith Wilkinson playing key roles, the Trojans rallied from a 13-point deficit early in the second half to beat Oregon 81-75 Thursday night to move into fourth place in the Pac-10.

"We just wanted to give ourselves a chance to get into the (NCAA) tournament," said Mayo, who bounced back from his worst game of the season to score 18 of his 32 points in the final 8 1/2 minutes. "Every game down the stretch is pretty much must-win for us, especially at home."

Wilkinson, a 6-foot-10 junior who averages 2.1 points, 2.2 rebounds and 11.4 minutes per game, had nine of his career-high 11 rebounds in the second half, when he played 17 of his 23 minutes.

"I just boxed out and went up, the ball's were coming right at me," he said. "I loved being out there on the court. No points but 11 rebounds — not too bad. I'll take it."

Taj Gibson added 15 points and eight rebounds, freshman Angelo Johnson had 14 points and five assists, and Dwight Lewis scored 12 for the Trojans (16-9, 7-6 Pac-10).

"That was the best second half we've played this year on both ends," USC coach Tim Floyd said. "We certainly needed it. We got a great lift from Keith Wilkinson off the bench. O.J. and Dwight played much better defense in the second half.

"The difference in the game was we rebounded and guarded in the second half."

USC played without starting guard Daniel Hackett (stress fracture, lower back) for the second straight game. Hackett had a career-high 26 points, six rebounds and six assists in the Trojans' 95-86 overtime victory at Oregon last month.

USC had been winless in five games without Hackett.

"That was the big thing about this win," Floyd said.

Mayo, who had four points and 10 turnovers in USC's 56-46 loss to No. 6 UCLA last Sunday, made a 3-pointer with 6:12 remaining to snap a 61-all tie and put the Trojans ahead for good. He added another 3-pointer with 2:04 to play to make it 73-69, and the Ducks weren't closer than four points after that.

O.J. Mayo added six foul shots without a miss in the final 32 seconds to clinch the victory.

Mayo, who had scored in double figures in each of USC's first 23 games before the UCLA debacle, said Floyd pointed to him along with a couple of his teammates at halftime "who weren't guarding anyone."

Apparently, it made a difference.

"I said (at halftime) they must not want to go to the NCAA tournament," Floyd said. "If they wanted to, they must guard better."

Malik Hairston scored 17 points, Tajuan Porter had 16, Joevan Catron added 14 and Maarty Leunen had 10 points and eight rebounds for the Ducks (15-11, 6-8), who lost for the seventh time in 10 games.

"We worked so hard to get up, but the game was just too big for us," Oregon coach Ernie Kent said. "Give them credit — they started driving, driving, driving and getting all the rebounds."

A basket by Catron and four straight points by Hairston gave Oregon a 50-37 lead early in the second half.

Then, with Johnson and Wilkinson leading the way, the Trojans went on a 20-6 run to take their first lead, 57-56 with 9:15 remaining. Johnson scored eight points and Wilkinson led the way as the Trojans dominated the backboards during the spurt.

Neither team led by more than four points after that until the final two minutes.

"We had a great chance to win," Hairston said. "We were the aggressors early in this game. We just gave them more possessions (in the second half) and they capitalized on them."

Porter made two 3-pointers and Catron added a pair of baskets as Oregon took a quick 13-4 lead, and Porter added another 3-pointer to make it 22-10.

Mayo picked up his third foul with 3:15 left before halftime, but with the Trojans trailing 38-24 and USC having a thin bench, Floyd opted to leave him in the game.

The move paid off as Mayo's 3-pointer capped an 8-2 USC run to finish the half, cutting Oregon's lead to 42-33. Freshman LeKendric Longmire, averaging 2.9 points, scored eight in the opening 20 minutes, and the Ducks committed just one turnover.

Mayo wouldn't pick up his fourth foul until the final 24 seconds, when the outcome had been decided.

"With our lack of depth, we've got to take risks," Floyd said. "We played O.J. a lot with three fouls. He's determined and very bright. He understands his foul trouble."