Alex Avila’s first career grand slam broke a 1-1 tie in the sixth inning for the Tigers.

Avila sent a 2-1 pitch over the fence in right with two outs off Nationals ace Stephen Strasburg. It was the first time Strasburg had given up a home run with more than one man on base.

The Tigers went on to beat the Nationals 5-1 on Tuesday night in front of 41880 at Comerica Park.

Anibal Sanchez allowed five hits two walks and one run over seven innings with one strikeout for the Tigers. Sanchez leads all active pitchers with at least 15 starts against the Nationals with a 1.99 ERA.

“It was what it was supposed to be a pretty good pitchers’ duel” said Tigers manager Jim Leyland. “Sanchy did what he had to do. You knew you weren’t going to get many. We finally opened it up with that big hit.

“You put four on the board with one swing of the bat that’s pretty good.”

Right-handed pitcher Jose Veras acquired in a trade from the Houston Astros on Monday for minor league outfielder Danry Vasquez and a player to be named made his debut for the Tigers in a 1-2-3 eighth inning. He got a pair of groundouts and a fly out to center on 14 pitches.

Strasburg (5-9) allowed six hits three walks and five earned runs in seven innings with seven strikeouts.

“I pitched well minus one pitch” Strasburg said. “It’s tough. It’s baseball. I tried to throw a fastball away and it came back over and he put a good swing on it. They’re obviously a really good-hitting team. ... I told myself after it happened I’m not going to give in. ... And I was able to recover pretty well after that.”

Leyland said: “I was really proud of the way the guys grounded out their at-bats tonight. That’s a tough pitcher. I mean that’s as good a stuff as you’re going to see really.”

The Nationals took a 1-0 lead in the first inning off Sanchez. Bryce Harper led off with a triple to right and came home on Ryan Zimmerman’s single to center.

The Tigers tied the game at 1-1 in the fourth inning. Andy Dirks hit a ground-rule double to bring home Prince Fielder.

“We gotta get him going a little bit” Leyland said of Dirks who finished 2-for-4. “He got another hit off a left-hander so that’s a good sign.

Jhonny Peralta would have scored on the play to give the Tigers a 2-1 lead but he was returned to third base due to fan interference. A fan along the third-base line had leaned over the rail with the ball in play and scooped it up with his glove.

“I thought the umpires called it correctly” Leyland said.