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 tonight.

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 1-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. Washington (6-3) came close to scoring a touchdown only once — when Campbell threw incomplete to eligible lineman Lorenzo Alexander on fourth-and-goal at the 1 in the fourth quarter. Campbell, who finished 24-of-43 for 206 yards, thought he had scored on a scramble on the previous play, but a replay challenge showed he was down just before the goal line.

While the Steelers remain atop the AFC North, the Redskins lost ground in the NFC East to the New York Giants. Washington enters its bye week needing to tweak an offense that has put together promising drives all season but has often struggled to find the end zone.

The game was the first hosted by Washington on the eve of a presidential election since 1984, and there was no mistaking the combination of football and election fever. One fan alternately waved a white towel with Barack Obama's image in the left hand and an all-burgundy Redskins towel in the right hand. Sports-themed interviews with Obama and John McCain were broadcast by ESPN during halftime.

The Redskins also used the special occasion to wear burgundy jerseys and pants together for the first time in franchise history. A more noticeable color, however, was the yellow from the sea of Terrible Towels waved by Steelers fans who managed to secure tickets by the boatload for the lower bowl of the stadium. In a bizarre sight, visiting Pittsburgh players were waving to the fans all around them to make noise crowd during defensive stands.

Neither team managed 100 yards in a first half that included seven sacks and a combined 13-of-32 performance by Roethlisberger and Campbell. The Redskins didn't convert on third down until Campbell hit tight end Chris Cooley for a 12-yard gain late in the third quarter.

Campbell's streak without an interception reached 271 attempts — 249 this season — before cornerback Deshea Townsend grabbed a pass tipped by Portis late in the third quarter.

Washington was on the board early with two field goals in the first four minutes — without the benefit of a first down. Linebacker Alfred Fincher alertly recovered the Steelers surprise onside kick that opened the game, and Cornelius Griffin intercepted a pass tipped by teammate Andre Carter. Both plays gave Washington the ball in Pittsburgh territory, leading to field goals of 44 and 43 yards by Shaun Suisham.

The Steelers didn't cross midfield until Carlos Rogers grabbed Hines Ward to commit an obvious 43-yard pass interference penalty, setting up a 35-yard field goal by Jeff Reed that cut Washington's lead to 6-3.

The Steelers went ahead after Andre Frazier blocked Ryan Plackemeier's punt. William Gay recovered, giving Pittsburgh the ball at Washington's 13 and setting up Roethlisberger's 1-yard TD.