MIAMI (Ticker) -- Cliff Floyd smacked a controversial two-run homer in the bottom of the seventh inning to help A.J. Burnett earn his first win of the year as the Florida Marlins managed a doubleheader split with a 6-1 victory over the Atlanta Braves.

With two outs and the score tied 1-1, Floyd -- who went hitless in four at-bats during Florida's 5-3 setback in Game One -- batted for Burnett.

He laced a 1-0 pitch from reliever Scott Kamieniecki over the right-center field fence for his 17th homer, which appeared to have been touched by a fan before it cleared the wall.

Right fielder Reggie Sanders argued for fan interference but second base umpire Laz Diaz ruled the ball had gone over the fence before the fan made contact with the ball.

"The thing about pinch-hitting is that you have no pressure," Floyd said. "You hope to get a good pitch and put a swing on it. I do give the ump credit, he went out there as far as he could."

The homer ignited a four-run frame capped by a two-run double by Mark Smith that propelled the Marlins to a 5-1 lead.

Burnett (1-0) pitched well in his first start since coming off the 60-day disabled list. He limited the Braves to just one run and three hits over seven innings, striking out six.

The 23-year-old righthander struck out four consecutive batters during one stretch and retiring 13 of the final 15 batters he faced.

"A.J. was huge for us after losing the first one and even for his first major league start (of the season)," Florida manager John Boles said. "He has a little giddy-up to his fastball and it catches them. He isn't rattled by anything. He's going to be a star. It's a walk in the park for him and it's good for him to have that confidence."

The decisive four-run frame ruined what was a strong outing by slumping Braves starter Kevin Millwood. He baffled the Marlins for six innings, allowing only a fourth-inning solo home run to Kevin Millar among five hits.

"I felt like I battled a little, but my curveball wasn't there," Millwood said. "They've got a team of hitters and give credit to A.J., he got the job done. I think everyone gets pumped up to beat us. They've got a good team, they've got what it takes to beat you."

Once Florida received the comfortable lead, Armando Almanza and closer Antonio Alfonseca shut down Atlanta by combining to throw two hitless innings of relief.

After not pitching in the major leagues since September 29, Burnett appeared a little hesitant during the opening frame. He plunked Andruw Jones with a pitch and allowed two consecutive singles, including a run-scoring base hit to Wally Joyner.

"I got a little caught up in the first, but settled down," Burnett said. "I'm happy to pitch with (the Marlins) and they are playing great ball. I'm happy to be a part of it."

Atlanta held on to the one-run advantage until the fourth when Millar lifted a 1-0 pitch from Millwood over the left-field wall for his career-high 10th homer.

Derrek Lee, who came on for Millar, greeted John Rocker with a solo homer in the eighth on a 3-2 pitch to cap the scoring.

Florida has won four of six games from the defending National League champions this season.