SEATTLE – When Clay Buchholz got into trouble in the second inning Wednesday night, Victor Martinez was right there to give his pitcher a big lift.

It was only the beginning.

Martinez made a couple of big throws from behind the plate and hit a two-run double to help the Boston Red Sox beat the Seattle Mariners 5-1 on Wednesday night, completing a three-game series sweep.

Seattle had a 1-0 lead and runners on second and third with no outs in the second when Martinez made a nice throw to Adrian Beltre to pick off Casey Kotchman at third.

“You got two great players, one behind the plate and one playing third base,” Buchholz said. “When they’re on the same page and they can make things happen like that, all that does for a team is bring them up and want to get in the dugout and makes everyone want to get a hit.”

Buchholz (16-7) allowed one run, Russell Branyan’s first-inning homer, and four hits over seven innings in his first victory since Aug. 22. He was 0-2 with a 5.40 ERA in his previous three starts.

Buchholz acknowledged Branyan’s 25th homer “took a little wind out of me. But after that play at third base, that was definitely a big upside.”

David Pauley (2-8) pitched six strong innings for the Mariners, who have lost seven straight. Pauley gave up two runs, one earned, and six hits.

“It’s one of those things,” Pauley said of the lack of run support. “You go up against a guy like Buchholz, a guy who is having a phenomenal year, and you are facing some tough pitching.”

Martinez also threw out Chone Figgins trying to steal second in the third inning, denying him his 40th stolen base, as the Red Sox moved within six games of the AL wild card-leading Yankees.

But it was the play at third that got most of the attention after Boston’s fourth straight win.

“They’re in the midst of what looked like a big inning,” Red Sox Manager Terry Francona said. “That’s happened a couple times now. Communication was good. It was a big play for us.”

Martinez and Beltre both noticed that Kotchman was straying too far off the bag. They signaled to each other.

“We had to take a chance, no outs,” Martinez said. “I always take that chance.”

For the Mariners, it was just another in a series of baserunning mistakes that have contributed to a woeful season.

“It’s frustrating,” Branyan said. “Do I have an answer? I’ve been part of it. We continue to get in those situations and continue to try to do more than what we need to do.

“Whether it’s a sense of urgency or what it might be, we’re not getting it done in those situations.”

Michael Saunders walked after Kotchman was cut down, but Buchholz got Adam Moore and Chris Woodward to ground out to end the inning. He did not allow a hit after Figgins’ two-out single in the third.

Beltre hit his 28th homer in the fourth and the Red Sox grabbed the lead in the sixth, taking advantage of an error by second baseman Figgins. With two outs and David Ortiz on third, Figgins let Yamaico Navarro’s grounder bounce through his legs untouched for an error.

Martinez hit his two-run double in the seventh against Ryan Rowland-Smith, and Ryan Kalish tripled in Marco Scutaro in the eighth.