MIAMI -- The Pittsburgh Pirates rediscovered their power to win consecutive road games for the first time in a month.
Pittsburgh hit a season-high four home runs following 12 games in which it hit a total of three homers.
Marlins reliever Kevin Gregg (0-3) retired the first two hitters in the 10th. Then Nady hit his second solo home run of the game to give Pittsburgh a 6-5 lead. Four pitches later, Doumit followed with his homer on a 1-2 count.
"I hit it good, but he obviously has good stuff -- he probably supplied most of the power," Nady said.
"It was a fastball down and away, and he did a good job," Gregg said. "He went down and got it."
The Marlins have lost four straight games overall and 11 of their last 14 home games. Florida fell to 1-5 in extra-inning contests.
"It's not that we're flat, we're not getting the hits when we need to," manager Fredi Gonzalez said.
Carroll ran for Josh Willingham, who opened with a single, and took second on Miguel Olivo's single.
Florida's Hanley Ramirez homered in his return to the leadoff spot for the first time since May 14.
Sergio Mitre gave up five runs and seven hits in six innings for the Marlins. He walked three, struck out five and allowed multiple home runs for the first time this season.
Pirates starter John Van Benschoten allowed two runs and three hits in four innings. He walked five, struck out three and threw 81 pitches.
"I felt horrible," Van Benschoten said. "Four innings is not what you want. It was almost like I was drawing a blank."
Bautista hit a two-run homer in the third and Nady homered leading off the fourth to help Pittsburgh build a 3-0 lead.
Olivo hit a run-scoring double in the Florida's two-run fourth but Pittsburgh scored twice in the fifth to make it 5-2. Adam LaRoche hit an RBI single and Jason Bay had a sacrifice fly for the Pirates.
Ramirez led off the seventh with his 11th home run, off reliever Masumi Kuwata.
Pittsburgh earned consecutive road victories for the first time since a three-game winning streak May 25-27.
"We showed some perseverance," Doumit said. "This was big to take this series."
- The Marlins are 14-21 when Ramirez leads off and 21-18 when he bats third.
- Before the game, Florida put Aaron Boone (sprained left knee) on the 15-day disabled list, retroactive to June 25. OF Todd Linden was called up from Triple-A Albuquerque.
- It was Nady's third career multihomer game and the first by a Pirates player this season.