DETROIT – Dustin Pedroia’s untimely bobble and a pair of four-pitch walks by Jake Peavy cost the Boston Red Sox a chance to take control of the A.L. Championship Series.

Detroit scored four of five runs off Peavy in the pivotal second inning after Pedroia fumbled away an opportunity at a critical double play, and the Tigers beat Boston 7-3 Wednesday night to tie their best-of-seven playoff at two games apiece.

“That was my fault,” Pedroia said.

Peavy, likewise, wasn’t happy with himself.

“Just couldn’t make the pitches to minimize the damage,” he said. “No excuses. It’s on me.”

Peavy picked a bad time to have his worst performance of the year. Acquired in late July as part of a three-team trade that included the Tigers, the right-hander allowed a season-high seven runs in three-plus innings.

“You can’t give guys a free pass and I did that,” he said.

Three times, in fact. All in the second inning.

Peavy, though, didn’t get much help from Pedroia during Detroit’s big rally.

Boston’s normally sure-handed second baseman booted a sharply hit grounder that could have been converted into an inning-ending double play. Instead of holding the Tigers to one run, the Red Sox settled for a force at second and Detroit took advantage by scoring four more.

“He’s so consistent. He’s such a good defender,” Boston manager John Farrell said. “He squares it up and typically that’s a routine double play we’ve seen many, many times over. Like I said, it handcuffed him a little bit, just enough to not be able to turn a double play.”’

Peavy gave up five hits in his shortest start since June 4, when he was still with the Chicago White Sox. The Tigers helped Boston acquire Peavy in a three-team deal less than three months ago that netted Detroit rookie shortstop Jose Iglesias.

“Peavy has pitched so many great games against us when he was in the Central, but he had a different approach than he usually does,” Detroit’s Torii Hunter said. “He threw a lot of off-speed pitches and he left a lot of them up. We were able to take advantage of that and get some big hits.

“He’s usually right around the plate, but there were times that he wasn’t even close.”

Victor Martinez hit a leadoff single in the second off Peavy, making his first appearance in a league championship series game. Peavy walked Jhonny Peralta on four pitches and gave Alex Avila a free pass in an eight-pitch at-bat to load the bases.

After getting Omar Infante to pop up, Peavy walked in the game’s first run when he failed to throw one strike to a slumping hitter.

Austin Jackson, who entered batting .091 in the postseason, didn’t have to swing during a four-pitch walk that made it 1-0. It was just the second time in Peavy’s 13-year career that he gave up a pair of four-pitch passes in one inning, excluding intentional walks, according to STATS.

“It looked like he was trying to be a little bit too fine in that second inning,” Farrell said.

But if Pedroia hadn’t bobbled the ball, the Red Sox would’ve escaped trailing by only a run.

“I think we probably contributed to the building of the inning, things we have control over,” Farrell said.

Boston had 12 hits, but went 2 for 16 with runners in scoring position and stranded 10 overall.