MIAMI -- Scott Olsen didn't sound all that impressed.
"It was not a great game, but the strikeouts make it look good," he said.
Florida led 5-0 after two innings and 8-2 before Pittsburgh closed with five runs in the seventh.
Adam LaRoche had a two-run homer for the Pirates, who lost for the sixth time in eight games. Hanley Ramirez's leadoff triple in the bottom of the first started a four-run inning, and Pittsburgh never recovered.
"Obviously, it was a very one-sided game in the first four innings and we did a great job to get back in the game," Pittsburgh manager Jim Tracy said.
Olsen (6-6) gave up five runs and seven hits in six-plus innings, becoming the first Marlins pitcher to start a game with five strikeouts. His career strikeout high was set in a 4-1 win over the Pirates in Miami on July 21, 2006.
"He was outstanding," Florida manager Fredi Gonzalez said. "The last three to four starts he has pitched, he is getting to where we want him."
Olsen threw 108 pitches.
"The pitch count got a little high," he said. "Obviously strikeouts are momentum when you get them in a row like that."
Kevin Gregg gave up a single to Freddy Sanchez leading off the ninth, then got three straight outs for his 15th save in 15 opportunities. On Wednesday, Gregg gave up 10th-inning homers to Xavier Nady and Doumit in a 7-5 loss.
"He wanted to be back out there," Gonzalez said. "This guy's arm is resilient. We were worried about the short turnaround, less than 12 hours, but you saw today that his velocity was good and he is fine."
Zach Duke (3-7) allowed six runs and 12 hits in four innings, dropping to 1-2 in six June starts.
"Honestly, I could have made some better two-strike pitches," Duke said. "I made them to where they could put the bat on the ball. They're a team that chases pitches out of the zone and I didn't execute those pitches."
After Ramirez's triple to right, which bounced off the glove of Nady and rolled to the wall, Dan Uggla and Jacobs hit RBI singles and Brett Carroll had a two-run single, the first RBI of his major league career. Miguel Cabrera made it 5-0 with an RBI double in the second.
LaRoche, who entered in a 2-for-24 slump, had hits in his first two at-bats, including a fourth-inning homer.
Todd Linden hit an RBI single in the bottom half, and Treanor boosted the lead to 8-2 when he homered off Tony Armas in the sixth.
Jose Castillo's run-scoring double chased Olsen in the sixth. Matt Lindstrom relieved and gave up Bautista's RBI single, Sanchez's run-scoring double, Jason Bay's RBI groundout and Nady's run-scoring single.
Taylor Tankersley came in and gave up a double to LaRoche that put runners on second and third. Justin Miller then retired Ronny Paulino on an inning-ending flyout.
Florida boosted its lead in the eighth when pinch-hitter Alfredo Amezaga tripled off Shawn Chacon leading off and Ramirez singled to shallow center.
- Treanor has three homers in 401 major league at-bats.
- Josh Beckett struck out his first four batters against Seattle on June 9, 2005.
- Of the 31,628 paid attendance, 21,402 were a result of Camp Day, making it the largest group sale in franchise history.