Peter Diana, Post-Gazette Steelers kicker Jeff Reed celebrates with lineman Max Starks after drilling a 40-yard game-winning field goal. Click photo for larger image. More Steelers Batch prepares to take the reins Steelers Notebook: Injured Maddox to miss 3-4 games Steelers Photo Journal: Game Four: Steelers at San Diego Chargers

SAN DIEGO -- The Steelers pulled out an electrifying victory last night that was dulled somewhat when quarterback Ben Roethlisberger left the game with a knee injury in the final 65 seconds.

Jeff Reed kicked a 40-yard field goal with six seconds left to lift the Steelers to a 24-22 victory.

Roethlisberger limped off the field with 1:05 to go after guiding the Steelers to within striking distance of the winning score. Preliminary indications were he had a hyperextended left knee. He will have an MRI today in Pittsburgh.

"I'll be all right," said Roethlisberger, as he pulled on a pair of bluejeans over the knee, which was not wrapped. "You know me, I'm tough."

He had just completed a 9-yard pass to Antwaan Randle El to the Chargers' 29 when defensive end Luis Castillo rolled into his knee.

Charlie Batch replaced Roethlisberger and handed off three consecutive times to Jerome Bettis, who gained 21 yards on seven carries on the winning drive. He got the ball to the 22 and Reed got the call for the attempt.

"He came through big for us," coach Bill Cowher said of Bettis, who led the Steelers with 54 yards on 17 carries and scored a touchdown in his first action of the season.

Cowher told his team yesterday morning to expect "a battle of wills," and the game and atmosphere inside Qualcomm Stadium was all of that.

Chargers fans waved white towels, thousands of Steelers fans twirled their gold Terrible Towels and four black Navy helicopters from the city where Top Gun was filmed buzzed over the largest crowd in San Diego football history.

The electricity pulsated throughout the first Monday night game in nine years in San Diego, and the teams on the field responded in kind.

"That was a classic football game," Cowher said. "I think we were just fortunate enough that we had the ball last."

The Steelers raised their record to 3-1 and made amends after losing their previous game to the Patriots on a last-second field goal. The Chargers fell to 2-3 before their largest crowd ever, 68,537.

Roethlisberger ran for one touchdown on a 7-yard draw play and threw for another of 16 yards to rookie tight end Heath Miller. Bettis, playing in his first game after returning from a preseason calf injury, scored from the 1. The Chargers scored on Drew Brees' 11-yard touchdown pass to tight end Antonio Gates, LaDainian Tomlinson's 2-yard run and Nate Kaeding field goals of 34, 32 and 41 yards.

Roethlisberger completed 17 of 26 passes for 225 yards and remained without an interception for the season.

He did lose one fumble that appeared to be an incomplete pass. In the first quarter, San Diego linebacker Shawne Merriman came from his left outside and hit Roethlisberger as he was throwing. The Chargers recovered the loose ball, and the officials ruled it was a fumble. Replays seemed to show Roethlisberger's arm coming forward but Steelers coach Bill Cowher didn't challenge the call.

Their next drive would be more eventful.

The Steelers moved from their 16 to the 36 on a pass interference call, then up stepped Hines Ward. He caught a 12-yard pass and three plays later scored on a 47-yard pass that was overturned by replay. Ward fell down after gaining 14 yards but the officials ruled he was not touched. Replay showed that cornerback Quentin Jammer got a piece of Ward's right foot with his left hand.

Roethlisberger came right back for a 21-yard pass to Randle El. Roethlisberger then set up in the shotgun formation on third down and ran a quarterback draw up the middle behind the blocks of Cedrick Wilson and Verron Haynes for a 7-yard gain and a 7-0 lead with 9:14 left in the first half.

The Chargers put together a drive of their own that linebacker James Harrison rudely ended with an interception and 25-yard return.

The Steelers made that pay off when they moved 41 yards on seven plays to score. Bettis dived off left guard from the 1 for the touchdown that put the Steelers in front, 14-0, with 1:37 left.

That's when the Steelers' kick coverage team had problems. Their troubles against the New England Patriots continued two weeks later when rookie Darren Sproles returned Reed's kick 48 yards to the Steelers' 47.

The Chargers picked up 36 yards in one hunk when Eric Parker caught a 23-yard pass and another 13 was tacked on when safety Chris Hope brought him down by the facemask. Gates then beat cornerback Ike Taylor on an 11-yard touchdown pass with 34 seconds left that cut the lead to 14-7.

Early in the third quarter, the special teams seemed to make amends when Chidi Iwuoma recovered a muffed punt return by Sproles, who had called for a fair catch, at the Chargers' 22. However, officials huddled for several minutes and ruled that Iwuoma did not give Sproles an unmolested chance to catch the ball. Cowher later concurred with their judgment.

Instead of possibly trailing by two touchdowns, San Diego used its second chance to close to 14-10 on Kaeding's 34-yard field goal.

Kaeding cut that lead to 14-13 when he kicked a 32-yard field goal on San Diego's next drive.

Cowher's teams had a 92-1-1 record when leading by more than 10 points, a .984 percentage that is the best of any coach in NFL history.

San Diego threatened to lower that number when they took a 16-14 lead with 11:41 remaining on Kaeding's third field goal, from 41 yards.

It lasted barely a minute.

Quincy Morgan returned the Chargers' kickoff 37 yards to the 38 and then Roethlisberger threw three pitches to strike out the Chargers. His first two went to Ward for 33 and 13 yards, and his third went to Miller for 16 yards and a touchdown. Three plays, 62 yards in 1:03 and just like that the Steelers were back in front, 21-16.

However, the Chargers weren't finished. They scored on their next series after another decent return against the Steelers started them on their 38. They reclaimed the lead on Tomlinson's 2-yard run with 4:42 left. The Steelers stuffed Tomlinson on the 2-point conversion try and San Diego went ahead, 22-21.

"I thought that was huge," Cowher said of the two-point stop.

That's when the Steelers mounted their winning drive, after Wilson returned the kickoff 29 yards to the 38 with 4:36 to go.