This would have seemed impossible two weeks ago, but the No. 24 Cal football team has now gone two full games without scoring a touchdown. Against USC, it even took a step backward from its typical knock of being one-dimensional.

"We were zero-dimensional today," coach Jeff Tedford said after his team's 30-3 loss to the No. 7 Trojans, "because we couldn't run it and we couldn't throw it."

The offensive impotency in Oregon that was treated as an aberration now looks more like the beginning of a disturbing trend. Short bursts of offense by the Bears are getting lost in an overall inability to sustain drives. A nearly unstoppable force at the beginning of the season, Cal has now scored six points in eight quarters.

And the Bears continued their fall from grace Saturday night with another embarrassing loss -- this time at home -- against another opponent that they were supposed to be battling for the Pac-10 title, which is now a long shot at best. Since its 3-0 start, Cal (3-2, 0-2 in the Pac-10) has played like a different team with the ball, and the players are still struggling to figure out what has changed.

"It's real frustrating," tailback Jahvid Best said. "We move the ball up and down the field and then we just can't finish it, so it's real frustrating.

"We feel like we're playing the exact same, but we're making little mistakes here and there that just keep holding us back."

Best and others gave the same explanation last weekend in Eugene -- "We're just taking turns messing up." -- and no player gave any hint that there are bigger issues underlying the recent dropoff in production. But if they haven't already, people are going to start looking at this offense that averaged 48 points in its first three games and features the most explosive running back in the nation and wonder: How?

"It's got to be pretty concerning right now, not finishing those drives," quarterback Kevin Riley said. "Last week, we started off going down (the field), getting stopped, and this week it happened a few times. It's just something you've got to do to win games is put the ball in the end zone, and we're not doing that right now."

If USC (4-1, 2-1) was supposed to be vulnerable coming into this game, it didn't show. The Trojans' defense held Cal to 86 rushing yards -- 47 by Best, whose Heisman Trophy candidacy took a fatal hit -- and Kevin Riley to 15 completions on 40 attempts for 199 yards and no touchdowns.

Riley was sharp to start the game, leading the Bears to the USC five-yard line on their opening drive. But he forced a throw to the back of the end zone on third down that was intercepted by Trojans safety Taylor Mays -- the first of five drives that stalled in USC territory and yielded no points -- and wasn't consistent for the rest of the game. He overthrew multiple receivers, notably Best on a short pass on fourth-and-two from the Trojans' 38-yard line that would have gone for an easy first down.

That play ended a drive on which Cal's offense primarily ran the Wildcat, snapping directly to either Best or Shane Vereen on five out of eight plays.

Asked if his confidence was shaken after the game, Riley said, "I'm fine. Just got to play better. All the confidence in the world, just got to go out and do it."

Best, meanwhile, was a non-factor through much of the first half. During one stretch of three drives, he touched the ball just once -- and that on a reverse play that he flipped to receiver Jeremy Ross for an eventual no-gain. His longest run was 13 yards, and his two catches went for just five.

"Against a great running back you want to get to him early, and that's what we did," Trojans coach Pete Carroll said. "We never let him get into a rhythm. Because of that they had to pass the football, and that's what we wanted."

Carroll's plan was probably influenced in part by last weekend's performance against Oregon, when the Ducks pressured the line of scrimmage to stop Best and the Bears couldn't take advantage in the passing game. On Cal's second play of the game, the Trojans crowded the box with nine defenders. For the second week in a row, it worked.

"(Best is) a big part of this offense and when we can't get him going, it's frustrating," Ross said.

USC, on the other hand, had little trouble moving the ball on offense, racking up 457 total yards. Tailback Joe McKnight ran for 121 yards on 20 carries and scored twice, while quarterback Matt Barkley went 20-of-35 for 283 yards. The Bears' defense had stressed the importance of putting pressure on the true freshman Barkley, but were mostly unsuccessful.

"We tried," defensive coordinator Bob Gregory said. "I think they picked up a lot of stuff. They've got a very good offensive line, very athletic."

Still, it was Cal's defense that kept this game from getting too far out of hand. The Bears allowed several long drives but tightened up in the red zone after giving up a touchdown on the opening drive. Until a fourth-quarter touchdown run by McKnight, they allowed only three field goals and stopped USC on downs twice.

"I think we pressed it, played a little bit tight early, missed some tackles because we were trying so hard," Gregory said. "But I think we calmed down a little bit and played pretty decent.

"Told them afterward -- very, very proud of them. They battled the whole way."

The Trojans' third touchdown came on a 66-yard punt return by Damian Williams early in the second quarter.

Cal heads into its bye week with plenty of wounds to lick. Players were torn after the game on whether they would rather have the time off to recuperate or a game next week with which to rebound, but the fact remains that something must be done to right the ship before the Bears play UCLA in Pasadena on Oct. 17.

"I don't know what's going to happen against UCLA," Tedford said. "All I know is I have a lot of confidence that we will prepare well and they'll have good attitudes, and there's a lot of football left to be played. We're still 3-2 and there's a lot of football left to be played. There's no way in the world that we're folding our tent. I don't believe that in this team."

Tags: JAHVID BEST, KEVIN RILEY, JEFF TEDFORD, CAL, CALIFORNIA GOLDEN BEARS, CAL FOOTBALL