Tonight, the national championship of college football was upstaged by a quarterback who played almost an entire game limping on his injured left knee.

Brigham Young's Robbie Bosco, who returned in the second quarter after straining ligaments early in the game, threw a 13-yard touchdown pass to halfback Kelly Smith with 1:23 remaining to lead the nation's top-ranked team to a 24-17 victory over Michigan in the Holiday Bowl.

The margin was enough to ensure the Cougars a perfect 13-0 season. But will it be enough to secure the national championship Jan. 2?

Surveys of wire-service poll voters indicated the Cougars, who are considered to play a relatively weak schedule, would have to win impressively to keep their ranking. They hardly did that, surviving six turnovers and needing a 14-point comeback in the final 11 minutes to beat unranked Michigan (6-6), the sixth-place team in the Big Ten.

But give them the red badge of courage, if not the title. The Cougars won with a quarterback who was, in the words of Coach LaVell Edwards, "in tremendous pain."

Bosco kept hobbling back onto the field, and even scrambled several times, and finished with superb statistics. He completed 30 of 42 passes for 343 yards and two touchdowns, along with three interceptions. What would he have done if he were healthy? If this performance doesn't play in the wire services, it certainly will go over big in Hollywood.

"As long as I could walk, I was going to stay in," he said. "Sometimes I wondered whether or not I was letting the team down, but things began to click for us in the fourth period.

"In my mind, there's no question we should stay No. 1."

Bosco, a junior who was the nation's leader in total offense, was hurt on BYU's second possession. From his 28-yard line, he dropped back and, as he let go of the ball, was clobbered by defensive tackle Mike Hammerstein.

Hammerstein was called for a personal foul, but it was nullified by an illegal procedure penalty on BYU. That was the least of BYU's worries as Bosco was carried to the sideline, then to the locker room.

Without Bosco, BYU struggled. The Wolverines, lumbering up and down the field as if this were just another Big Ten weekend, put the game on cruise-control and kept it close, just as they wanted.

The Cougars scored first; appropriately enough, just after Bosco returned from the locker room to the cheers of the vast BYU majority in the crowd of 61,243 at Jack Murphy Stadium. Bosco was gimpy, but no one could doubt Edwards' decision four minutes later when Smith took a handoff from the Michigan five and charged into the end zone for a 7-0 BYU lead.

Bosco worked from the shotgun formation for all but the final play of the 11-play, 80-yard drive, and completed five of the seven passes he threw. He also scrambled -- slowly -- 13 yards on a third-and-five play to the Michigan 26.

Michigan could do absolutely nothing with the ball, forcing punter Monte Robbins to drop back inside his 10-yard line to kick. But five BYU defenders broke through the Michigan line, and Robbins, uncertain what to do, ran sideways and was shoved out of bounds at the five.

A certain BYU touchdown? Not quite. On third and goal at the two, Bosco curiously sprinted out and tried to run inside. As he dived near the one, he lost the ball, and Michigan's Kevin Brooks landed on it in the end zone for a touchback.

Michigan finally got its offense untracked, thanks to a little dabbling with the forward pass. Quarterback Chris Zurbrugg, starting his fifth game of the season after injuries took out two other Michigan quarterbacks, threw to split end Vince Bean for a 20-yard gain, and later found Bean again for 13 more.

It seemed Michigan would be forced to settle for Bob Bergeron's 32-yard field goal, but BYU's Cary Whittingham was called for roughing the kicker, and Michigan was in business at the 10. Rick Rogers ran five yards, then, on second down, went up the middle for a 7-7 tie.

With 1:08 left in the half, Bosco led the Cougars 69 yards on eight plays to Lee Johnson's 31-yard field goal with four seconds remaining.

Michigan went ahead, 14-10, on Bob Perryman's 10-yard catch with 19 seconds left in the third quarter. The Wolverines put together a masterful 47-yard drive, but give credit where it was due: to BYU futility.

The drive began on a blocked 52-yard field goal. The Cougars' previous drive ended when Bosco fumbled. The drive before that was finished by an interception.

Michigan could not capitalize on the first two mistakes of the second half, but that hardly seemed to matter. A standoff favored the Wolverines, who appeared to be biding time.

Finally, the Wolverines couldn't help but score. After Erik Campbell ran 25 yards with the blocked kick, Perryman gained 25 against the grain to the BYU 18. Three plays later, on third and two, Zurbrugg threw to Perryman at the three, and he turned into the end zone.

Moments later, BYU's Lakei Heimuli fumbled at his 11, setting up Bergeron's 32-yard field goal and it was 17-10. But the Cougars answered, finally, on Bosco's seven-yard pass to Glen Kozlowski deep in the end zone with 10:51 to play.

Bosco was six of six in the 80-yard drive that tied the game, 17-17.

Michigan Coach Bo Schembechler was asked, afterward, if he thought Bosco had performed courageously.

"I don't know how bad he's hurt," he growled. "I'm not a doctor."