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

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 on May 2 when fellow third baseman Kevin Youkilis went on the disabled list, Nava on 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 that we can come through and help them win,'' said Middlebrooks, 23. ''So 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 took a lead in all three games but lost them all as they dropped their fourth straight overall and 13th in their last 15.

''This hurt a lot,'' Miami manager Ozzie Guillen said. ''We've got to come back with a winning attitude. Fight for it. Good fighter fight the fight. Bad fighter throw in the towel.''