Jeremy Hermida hit a pinch-hit home run to lead off the ninth inning to help the Florida Marlins to a 3-2 win over the Chicago Cubs on Friday.

Justin Miller (3-2) earned the win by getting the final two outs in the eighth inning, and Kevin Gregg earned his 21st save by pitching a perfect ninth.

Bobby Howry (3-4) entered in the ninth and took the loss, after Hermida's home run on a 3-2 pitch. Geovany Soto and Reed Johnson hit solo homers for the Cubs, who fell to 3-5 since the All-Star break.

Chicago's Jeff Samardzija, the former Notre Dame football star, made his major league debut after being called up from Triple-A Iowa before the game.

Samardzija came in to protect a 2-1 lead in the seventh, but couldn't hold it.

With two outs, Jorge Cantu doubled in Hanley Ramirez to tie the score, but Samardzija avoided any further damage by getting Mike Jacobs to pop up to second baseman Mike Fontenot.

His second inning went smoother, as he retired the side in order. He ended up allowing one run and two hits with two strikeouts in two innings.

Samardzija received a standing ovation — his first of many — when he took the mound, and the crowd cheered when he struck out pinch-hitter Alfredo Amezaga to lead off the seventh.

While he showed some wildness — badly missing Soto on a pitch out — he also displayed a fastball that was clocked at 99 mph on the stadium radar gun.

Cubs starter Ryan Dempster tired during a hot day at Wrigley.

Dempster opened the second inning by hitting Dan Uggla, who had been hitless in his previous 13 at-bats. Josh Willingham made Dempster pay by doubling to right-center field to score Uggla.

Dempster allowed two hits and struck out six, but walked a season-high six in six innings. In the fifth, Dempster got the first two men out before walking the bases loaded. He then struck out Uggla to get out of the jam.

Florida starter Josh Johnson also tired in his third start of the season after undergoing elbow surgery on Aug. 3.

Johnson overpowered the Cubs early, striking out four of the first five batters before Soto hit his 17th home run of the season in the second inning.

Johnson matched a career high with eight strikeouts in 5 1-3 innings. He gave up two runs and seven hits with three walks.

Reed Johnson homered in the fifth to break a 1-all tie. The Cubs were in position to score more in the inning with Alfonso Soriano on second and Ryan Theriot on first, but Soriano was thrown out at the plate by Willingham on a Derrek Lee single to left field to end the inning.

Notes:@ Luis Gonzalez doubled in the first inning, but was then walked by Dempster his next two times up. Gonzalez is 11-for-19 (.579) lifetime against Dempster. ... Ryan Theriot had two hits Friday, and leads the NL with 41 multihit games. ... Samardzija is taking the roster spot of closer RHP Kerry Wood, who was placed on the disabled list Thursday, retroactive to July 14, with a blister on his right index finger.