NEW YORK (AP) -- Dontrelle Willis made up his mind on his way to the plate. With the bases loaded in the fourth inning Friday night and New York Mets starter Jose Lima struggling, Willis decided he would swing at the first pitch.
"He was having trouble with his command," Willis said. "I thought, 'I'm going to swing at whatever he throws.'"
Lima made a mistake and Willis sent it soaring an estimated 405 feet over the right-field bullpen, capping a six-run Florida Marlins rally in a 7-3 victory.
"Everybody says I swing hard," Willis said. "Once in a blue moon, maybe you run into something. Today was that blue moon. I was happy because it put four runs on the board and put momentum on our side. It was important. We won by four."
The slam was the first by a major-league pitcher since Philadelphia's Robert Person connected on June 2, 2002, against Montreal, according to the Elias Sports Bureau.
It was Willis' fourth career homer, first this season, and the first grand slam hit by the Marlins this season.
Florida, which has scored 32 runs in the past three games, won for the second time in seven tries and snapped the Mets' three-game winning streak.
New York's All-Star shortstop, Jose Reyes, left in the seventh inning with a cut on his left pinkie. He appeared to get spiked on a headfirst slide into first base and took seven stitches in the finger. X-rays were negative.
"Everything is fine," he said.
Reyes said he would sit out Saturday's doubleheader and Sunday's game.
The Marlins were up 1-0 against Lima (0-4) when Miguel Cabrera
opened the fourth inning with a walk. Lima, filling in because ace Pedro Martinez is on the disabled list with a sore hip, never recovered.
Mike Jacobs followed with a double, and an error by third baseman David Wright loaded the bases. Jeremy Hermida's bloop fell for a single, scoring Cabrera. Matt Treanor followed with another single, scoring Jacobs. Willis then completed the rally.
"It was a nice game for us," Marlins manager Joe Girardi said.
"We all know he's capable of doing that. It just gives us another weapon."
Pitching with the big lead, Willis (6-7) was touched up for three runs in the fifth. Chris Woodward homered and, after singles by Wright and Julio Franco, Xavier Nady's second double of the game drove in two more. Eli Marrero reached on an infield hit, but Willis struck out Ramon Castro, ending the inning.
The left-hander allowed nine hits, struck out nine and walked five in 7 1/3 innings. He ran his career record against the Mets to 9-2 with a 2.08 ERA.
After the game, the Mets designated Lima for assignment and added prized prospect Mike Pelfrey to the active roster. Pelfrey was called up from Double-A Binghamton to start the second game of Saturday's doubleheader against Florida.
Lima allowed seven runs and seven hits in three-plus innings. His ERA in four starts with the Mets was 9.87.
"Sometimes baseball puts you to the test," Lima said. "I want to be part of this championship. I want to be back. I cannot point fingers. They gave me a chance to compete. I didn't make my pitches."
The Marlins used the speed of leadoff man Alfredo Amezaga to score in the first inning.
Amezaga opened with a single and was running when Hanley Ramirez
grounded to third. Wright threw out Ramirez, but Amezaga kept right on running and scored when first baseman Franco's throw skipped past Wright for an error.
Willis got out of a two-on, none-out jam in the first, retiring Carlos Beltran on a fly ball before striking out Wright and Franco. Then Willis escaped a bases-loaded, two-out situation in the second when he struck out Woodward.
The next time the Mets had a baserunner, Willis had already homered and Florida had a 7-0 lead.
Josh Willingham's second-inning liner hit the left-field wall but rebounded so fast that he was held to a single . ... Willis retired the Mets on 10 pitches in the third. ... Mets reliever Darren Oliver allowed one hit over five innings with four strikeouts and two walks. ... Hard-throwing reliever Henry Owens made his major-league debut for the Mets, pitching a perfect ninth with one strikeout. ... Mets right-hander Mike Adams, designated for assignment on Tuesday, was claimed by the Cleveland Indians.