Ryan Howard's RBI double in the bottom of 1 victory over Florida in the second edition of a doubleheader.
Martinez worked a leadoff walk against Burke Badenhop (2-2), then Howard laced a double which bounced off the high wall in left-center, easily allowing the deciding run to cross the plate.
"I was just looking for something up. It looked like everything (Badenhop) was throwing was running away," said Howard of his crucial at-bat. "I was looking for something to shoot over to left field. Got to a 3-1 count and he led me a fastball down the middle."
It made a winner of Michael Schwimer (1-0), who turned in a scoreless top of the 10th to earn his first major league decision.
John Mayberry's sixth-inning solo homer was the only other offense for the Phillies, who won the opener by a 3-1 count and opened up a 12-game lead on idle Atlanta.
Cliff Lee was on track to record his seventh shutout of the season until a two-out homer by Jose Lopez in the top of the ninth. Nonetheless, the lefty wound up scattering five hits with 12 strikeouts over nine frames.
Alex Sanabia worked six innings, allowing just six hits and one run while fanning five for the Marlins, who have dropped four straight.
"Every one of the games we've lost, we've got one run. It's all been solo home runs," said Marlins manager Jack McKeon about his squad's output, which was limited to a Logan Morrison homer in the earlier contest. "We've got to up our quota (of scoring runs), otherwise we're gonna be in real bad shape."
Both starters allowed four hits over five scoreless innings, then Mayberry snapped the deadlock on a leadoff homer -- a low line-drive which landed just inside the foul pole in left.
Lee set down the side in order in the sixth, then followed suit in the seventh and eighth to preserve the slim margin.
Bryan Petersen struck out looking to start the ninth, then Raul Ibanez made a diving stop on a low liner to left from Mike Stanton for the second out. However, Lopez cranked a high, 0-2 pitch into the left-field stands to tie the game.
"It was supposed to be a backdoor cutter. I left it up out over the plate," Lee explained. "He hit a home run. That's really it. I just made a bad pitch."
Lee recovered to retire Omar Infante on a grounder to second.
It was the ninth time this season Lee has fanned 10-or-more batters, and the first since he struck out 10 in Los Angeles on August 9...This was also the Phillies' second doubleheader sweep against from the Marlins this year, marking the first time since 1983 (Montreal) that the club swept a pair of twinbills against one team in one season...Philadelphia took 12 of 18 from Florida in the season series...Both clubs are in action on Friday, as the Phils welcome St. Louis, and the Fish continue their four-city road swing in Washington...Florida fell to 0-3-1 in 2011 doubleheaders and 8-13 in extra- inning affairs.