DETROIT -- Ben Zobrist has seen opponents benefit from his team's miscues too often this season. When the Oakland A's caught a break on Tuesday night, Zobrist delivered a game-deciding blow.

Zobrist blasted a grand slam to cap a five-run eruption in the seventh inning and the A's held on for a 5-3 victory over the slumping Detroit Tigers at Comerica Park.

Detroit second baseman Ian Kinsler made a mental error two batters earlier, throwing home on second baseman Eric Sogard's grounder during a first-and-third situation instead of taking a sure out at first. All runners were safe, facilitating Oakland's outburst.

"It's big because I feel like it's happened to us more than us taking advantage of their mistakes," Zobrist said. "It had to turn around and it's been turning around gradually. We're fighting and battling to try to get back to the team we know we are. Tonight was definitely a good step in the right direction."

It was the sixth career grand slam for the Oakland left fielder, who had just one home run this season. Center fielder Billy Burns added two hits and an RBI and Kendall Graveman (3-2) pitched six innings to get the victory for the A's (21-33), who have won four of their last five games. Tyler Clippard pitched a scoreless ninth for his eighth save.

Zobrist's liner to right field off reliever Angel Nesbitt barely cleared the wall to give the A's a 5-3 lead. Nesbitt had just come in to relieve starter Alfredo Simon, who gave up an RBI single to Burns before departing.

"I didn't think it was going to clear, to be honest, when I hit it," said Zobrist, who was playing in his seventh game after missing a month with a left knee injury. "I knew I hit it hard enough to get it over (right fielder J.D. Martinez') head, so I was just happy about that."

Castellanos had a two-run single for Detroit (28-25), which has lost five straight and eight of its last 10. Simon (5-3) took the loss despite taking a shutout into the seventh. The Tigers were swept by the Los Angeles Angels during a four-game series before returning home.

"It's fair to say we're struggling," Tigers manager Brad Ausmus said. "I don't think that's a stretch by any means. When you are struggling, things like that (Kinsler's play) happen. On the night you hit, the other team hits more. On the night you don't hit, the other team scrapes out one. You need an out to get out of an inning, you can't get the out. That's just what happens when you're struggling. Anaheim was a slap in the face, this was a punch in the gut."

Kinsler expected A's third baseman Brett Lawrie, who was on third, to head home on the pivotal play.

"He thought the guy was in no-man's land and he could get him at home," Ausmus said. "If he could do it over again, he'd probably just take the out but it was an instinctual reaction."

The Tigers broke through with three two-out runs in the fourth. Detroit loaded the bases and Graveman uncorked a wild pitch that went to the outside with catcher Stephen Vogt set up inside. That allowed Detroit first baseman Miguel Cabrera to score from third. Castellanos then slapped a two-run single to the opposite field, bringing in two more runs.

Oakland had a bases-loaded opportunity during the top of the inning. Simon walked the bases loaded with two down, then retired A's shortstop Marcus Semien on a deep fly to right.

The A's got their first hit in the fifth when Burns singled with one out, but Simon induced Zobrist to hit into a double play.

NOTES: The Tigers made a series of roster moves on Tuesday. They purchased the contracts of INF Josh Wilson and OF Daniel Fields from Triple-A Toledo, optioned RHP Buck Farmer to Toledo and placed OF Rajai Davis on the paternity list. Davis is expected to rejoin the Tigers on Friday, according to GM Dave Dombrowski. ... Detroit SS Hernan Perez, who was out of options, was claim