LANDOVER, Md. --- Byron Leftwich led two touchdown drives after Ben Roethlisberger reinjured his throwing shoulder, and the Pittsburgh Steelers beat the Washington Redskins 23-6 on Monday night.

The Steelers' top-rated defense had seven sacks, allowed only 221 yards and became the first team this season to intercept Jason Campbell.

Leftwich went 7-for-10 for 129 yards and a touchdown as the Steelers (6-2) beat an NFC East team for the first time in three attempts this season.

Roethlisberger was 5-for-17 for 50 yards and an interception before leaving the game at halftime, again hindered by the slightly separated shoulder that has bothered him since the second week of the season.

Leftwich's 50-yard completion to Nate Washington set up a 1-yard TD run by Willie Parker, back from a four-week layoff with a knee injury. The quarterback also had a 5-yard scoring pass to Santonio Holmes, who returned from a one-game benching over a charge for a marijuana-related offense.

Roethlisberger scored on a 1-yard quarterback sneak late in the first half before leaving with an injury.

Roethlisberger's score with 32 seconds left in the first half made it 10-6. Leftwich, who played for the Falcons last season, replaced him and immediately led the Steelers to a touchdown.

After Parker's score, kicker Jeff Reed's extra point went wide left, leaving Pittsburgh with a 10-point lead.

Neither team was able to generate much offense, combining for 156 yards in the first half.

The Redskins didn't convert a third down until late in the third quarter. And Pittsburgh collected the first interception of Washington's Campbell this season, when cornerback Deshea Townsend grabbed a tipped ball late in the third quarter. Campbell had gone 271 passes without an interception, dating to last season.

Redskins tailback Clinton Portis, the NFL's leading rusher, was held in check, gaining 51 yards on 13 carries. Portis did manage to go over 100 yards from scrimmage, adding 73 yards receiving.