BOSTON – Down two runs in the eighth inning, Boston’s big guns had a chance to produce.

And Daniel Nava, Will Middlebrooks and Ryan Kalish did.

Who?

The three with a combined 113 games of major league experience before this season teamed for a three-run, eighth-inning rally Thursday night, and the surging Red Sox completed a sweep of the stumbling Miami Marlins, 6-5.

Boston tied the score on a two-run homer by Middlebrooks, who drove in four runs. Kalish then singled, raced to third on a groundout to first and scored on Nava’s go-ahead single up the middle.

“I love to see guys growing and learning and excelling at the same time,” Manager Bobby Valentine said. “It’s, I guess, a perfect combination.”

None of the three began the season in the majors.

Middlebrooks got there May 2 when fellow third baseman Kevin Youkilis went on the disabled list. Nava was called up May 10 and Kalish last Sunday.

Middlebrooks is batting .316 with eight homers and 31 RBI in 38 games while sharing time with Youkilis.

“It really hasn’t been bad” as a part-time player, he said. “I knew that was going to be my role and I just try to accept it.”

Nava is hitting.340 in 35 games, and Kalish is hitting .267 in four games. All three have been aggressive on the basepaths.

“When we were called up here, we wanted to gain (the club’s) trust and let them know we can come through and help them win,” said Middlebrooks, 23. “It’s good to see it happen.”

The Red Sox won their fifth straight game and seventh in their last eight as they matched their season-best mark of three games over .500.

Alfredo Aceves pitched a perfect ninth for his 18th save in 21 opportunities. Scott Atchison (2-0) allowed one hit over the seventh and eighth.

The Marlins led in all three games but lost them all as they dropped their fourth straight overall and 13th in their last 15.

Miami went ahead 5-3 with two runs in the sixth. Giancarlo Stanton, in a 2-for-31 slump, hit his first homer in 12 games and 15th of the season to make it 4-3. That ended Daisuke Matsuzaka’s streak of 14 straight batters retired, and brought in Andrew Miller.

Miller gave up a single to Greg Dobbs and a run-scoring double to Omar Infante.

Jarrod Saltalamacchia started the winning rally in the eighth with a double off Randy Choate. Edward Mujica (0-3) came in and served up Middlebrooks’ tying shot.

Then Nava, who had six singles in the last two games, lined a clean single to center.

“It’s fun to watch them, especially in a situation like that,” Atchison said. “We hit a two-run homer and then we play a little small ball to go ahead and take the game. It’s fun to watch. It doesn’t matter who’s doing it, but it’s really fun to watch these guys come up and contribute.”

In just his third start of the season since having Tommy John elbow surgery on June 10, 2011, Matsuzaka gave up a leadoff single in the first to Jose Reyes, who went to third on a slow grounder to shortstop Mike Aviles, who got the out at first. Stanton walked and stole second, and both runners scored on a single by Dobbs. After Dobbs stole second, he came in on a single by Infante.

Matsuzaka ended the inning by retiring Scott Cousins on a fly to center and didn’t allow another runner until Stanton homered.