Pittsburgh quarterback Ben Roethlisberger passes against Washington during the first quarter. Roethlisberger reinjured his throwing shoulder Monday in Landover, Md.

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.

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-of-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-of-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.

Roethlisberger said he hurt the shoulder on the one-yard sneak that gave the Steelers a 10-6 lead near the end of the first half.

“I have no update on Ben at this point,” coach Mike Tomlin said. “Potentially, he was capable of going back in the game, but we went down the field with Leftwich in there to start the second half. We’ll just see how he is.”

Roethlisberger spoke briefly in the locker room. Asked if the injury was serious, he said: “I hope not. We’ll find out.”

Leftwich’s 50-yard completion to Nate Washington set up a 1-yard TD run by Willie Parker, who was back from a four-week layoff with a knee injury. He 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 celebrated that touchdown on the sideline by high-fiving his teammates – with his left hand.

The Steelers held Clinton Portis to 51 yards rushing, ending his streak of five straight games with at least 120 yards.