Rashard Mendenhall spent last week on the bench, demoted by his coach because he did not know his assignments.

Last night, Mendenhall saved the Steelers' offense and perhaps his team's season when he rushed for 165 yards, two touchdowns and delivered on a final scoring drive that staved off a lightning comeback by the San Diego Chargers.

Mendenhall ran for 35 yards on a 51-yard drive that ended with Jeff Reed's 46-yard field goal with 43 seconds left to preserve the Steelers' 38-28 victory.

At one time the Steelers led by four touchdowns only to see the Chargers close to within one in yet another poor fourth-quarter showing by their defense. Nevertheless, they snapped a two-game losing streak to even their record at 2-2, one game behind co-leaders Cincinnati and Baltimore in the AFC North Division.

"He played a good game," Steelers coach Mike Tomlin said of Mendenhall, who had only 103 career rushing yards entering last night. "He had a good week's practice. I'm not going to take any credit for that."

Mendenhall, starting for the first time since his shoulder was broken in the fourth game of last season, combined with the pinpoint passing of Ben Roethlisberger to guide the Steelers to leads of 21-0 at the half and 28-0 in the third quarter before the Chargers stunned the Heinz Field crowd with quick scores in the fourth quarter that closed the margin to one touchdown with 4:31 to go.

Two touchdowns came on a strip of Steelers punt returner Stephan Logan and after a successful onside kick by the Chargers.

"We never make it easy, it seems," tackle Willie Colon said. Roethlisberger threw for 333 yards and two touchdowns, and Mewelde Moore caught one and passed for another as the Steelers achieved the kind of balance on offense they long have sought. Tight end Heath Miller caught two touchdown passes and Hines Ward had his second 100-yard receiving game of the season.

"It was a great day for the offense as a whole," Mendenhall said. "The offensive line did a great job controlling the line of scrimmage all game."

With starter Willie Parker out with turf toe, Mendenhall resurrected a run game that ranked 27th in the NFL entering the season.

Mendenhall scored his second touchdown in the first half, powering up the middle for 2 yards with 1:28 before halftime. He scored from the 1in the first quarter.

Making only his second NFL start, Mendenhall turned in a fabulous first half with two short touchdowns runs, 80 yards rushing, one catch for 20 yards, many broken tackles and two knockout blows on blocks.

The Steelers' first-round draft pick in 2008 answered many questions that have swarmed around him the past two seasons.

"He ran hard and he hit the holes hard," Colon said.

Mendenhall scored his first NFL touchdown from the 1 with 11:49 left in the first quarter. He ran hard on three consecutive plays from the 14, picking up 9, 4 and the final 1 for a 7-0 lead.

The Steelers threw a few wrinkles into their offense on that drive. Center/guard Doug Legursky lined up at fullback and Mendenhall ran behind his block into the end zone. Earlier, Logan lined up at wide receiver.

Roethlisberger came out throwing on that 79-yard drive, opening the game with three consecutive passes with the best being a 35-yarder to rookie receiver Mike Wallace.

Their next drive covered 75 yards and it began with four consecutive running plays by Mendenhall and ended with a touchdown pass of 19 yards from Roethlisberger to Moore. Roethlisberger beat an all-out blitz by seven Chargers by flipping the pass to Moore, wide open in the left flat. Moore then powered through two Chargers near the goal line for the score that put the Steelers in front, 14-0, with 4:08 let in the first half.

Their third touchdown came on their fourth drive of the half, and this one covered 79 yards on 13 plays. The biggest -- certainly the brassiest -- play of that drive came when Tomlin ordered his offense to go on fourth-and-1 at their 30. Roethlisberger made his coach look good, gaining 3 yards on a quarterback sneak.

Another key play on the drive came when Chargers cornerback Antonio Cromartie intercepted Roethlisberger but was called for holding receiver Santonio Holmes on the play. That gave the Steelers a first down.

Tight end Heath Miller caught a 12 yards pass to the 2 but fumbled and newly signed fullback Carey Davis recovered. Mendenhall then plowed up the middle for the score and a 21-0 lead.

The Steelers were quicker on their next drive, covering 81 yards in eight plays. The drive ended with Miller catching a 6-yard touchdown pass from Roethlisberger. It was the Steelers' fifth drive of the night and their fourth touchdown for a 28-0 lead.

San Diego finally broke the ice with a third-quarter touchdown pass of 3 yards from Philip Rivers to tight end Antonio Gates, who caught nine passes for 124 yards.

Matching the lightning bolts on their helmets, the Chargers scored again in quick and unique fashion. The Steelers forced them to punt from their 11, and Logan fielded the ball cleanly. However, as he was swarmed by a handful of Chargers, fumbled and Jacob Hester recovered and returned it 42 yards for a touchdown.

Just like that it was 28-14 with 12:37 left to play.

The Steelers scored again with 7:18 to go to seemingly take a comfortable lead, 35-14. But the electrified Chargers were not done. They moved 67 yards in a minute-and-a half to score on a 30-yard pass from Rivers to Gates with 5:48 left. That cut the margin to 35-21.

They then recovered an onside kick that went through the hands of Ryan Mundy and moved 54 yards on three plays, scoring on a 13-yard pass from Rivers to Chris Chambers. That made it 35-28 with 4:31 to go.

But Mendenhall and finally Reed put the game away.

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