The Associated Press

SAN FRANCISCO - Dozens of players reverently crowded around the cart to offer words of encouragement to Koy Detmer. The game was all but decided, and Detmer's fine play earned admirers in both uniforms.

As long as the Philadelphia Eagles don't run out of quarterbacks before the end of January - a distinct possibility at this rate - there might be no limit to how far their impressive offense can go.

Filling in tremendously for injured Donovan McNabb, Detmer passed for 227 yards and two touchdowns and rushed for another score before leaving with a dislocated left elbow late in the Eagles' 38-17 win over San Francisco on Monday night.

Detmer's big night began and ended with a fall. He tripped on the first play from scrimmage, and he hurt his elbow late in the third quarter, his legs flailing in excruciating pain after his awkward landing. Before he was carted off, the Eagles' entire bench emptied onto the field to wish him well along with the Niners' defense.

"It meant a lot to me," Detmer said. "I was in pain and disappointed at the same time. It was an incredible night up to that point. ... That was a great show of sportsmanship on (San Francisco's) part. They showed me a lot of respect."

Nobody will know how long Detmer will be out until he's re-examined in Philadelphia today, but third-stringer A.J. Feeley, who finished for Detmer, expects to start Sunday against St. Louis.

Before the fall, Detmer completed 18 of 26 passes while executing with remarkable precision for a player who'd thrown just 17 passes since 1999. McNabb is expected to miss the rest of the regular season with a broken ankle, but in Detmer's first start since 1999, he was outstanding for nearly three quarters.

"Koy's a pretty tough nut, so if he's rolling around out there, you know there's something wrong," coach Andy Reid said. "It wasn't a cheap shot or anything."

Using all of his many options in Reid's unpredictable game plan, Detmer carved up the 49ers' confused secondary and staked the Eagles (8-3) to a big lead. In particular, Reid picked on rookie Niners defensive back Mike Rumph incessantly.

Detmer, his arm still pulsating with pain after team doctors shoved his elbow back in its socket, stood on the sideline with a grin on his unshaven face, watching his teammates finish off the Niners in a one-sided meeting of division leaders.

Feeley hadn't thrown a pass all season, but hit Chad Lewis for a 1-yard TD moments after Detmer left - and the Eagles were all but assured of a conference victory that might turn out to be pivotal when playoff seedings are determined in five weeks.

"It always helps when you get some extra work," Feeley said. "Whoever's out there, we have confidence in the game plan."

Brian Mitchell returned a punt 76 yards for a touchdown, while Todd Pinkston and Antonio Freeman caught TD passes from Detmer as the Eagles mowed down the 49ers' defense even without McNabb or a consistent running game.

Terrell Owens had 13 catches for 166 yards and two TDs, but in spite of a warm night on Candlestick Point and the Eagles' desperate quarterback situation, the 49ers were terrible on both sides of the ball while losing at home for just the third time in two seasons.

The Niners (7-4) still lead the NFC West by two games, but they've lost consecutive games for the first time since midway through the 2000 season.

"We didn't play well all across the board," said Owens, who broke his month-old local media boycott. "I would say it's more embarrassing than frustrating. We know we didn't play up to form. We have our backs against the wall right now. We have a short week. We have to rest up and put this loss behind us."

Reid had his way with the Niners' defense, using a game plan that included plenty of reverses, play-action and misdirection - anything to keep the Niners' defense off balance and take the pressure off the backup QB. It worked: Detmer found Pinkston with a 25-yard TD pass early in the second quarter.

Detmer dived for a 1-yard TD midway through the third quarter to put Philadelphia up 28-10, and gave a quick arm-flap celebration similar to the one that got him a modicum of notoriety several years ago during a brief stint as the Eagles' starter.

Jeff Garcia was 29-of-51 for 284 yards as the Niners played from behind all night.

Notes: When Mitchell returned Jason Baker's punt for a score moments after Pinkston's TD catch, he became the NFL's career leader with 13 combined kickoffs and punts returned for scores. ... Freeman made an 11-yard TD catch 55 seconds before halftime to give a 21-7 lead to Philadelphia, and the Niners' fans booed their team off the field after another failed drive. ... Rookie Jeff Chandler kicked a 35-yard field goal for the 49ers in his first NFL game. San Francisco demoted Jose Cortez last week after he missed another potential game-winning field goal against San Diego.