Anthony Rizzo hit a three-run homer and Travis Wood won his fourth straight start, but not until after Marmol caught a line drive and started a game-ending double play that blunted the New York Mets' bid for another ninth-inning comeback, giving Chicago an 8-7 victory on Friday night.
"It was getting interesting but he pulled it off," Wood said.
Mets star Johan Santana was tagged for a career high-tying 13 hits in only 4 2/3 innings.
A night after they got two runs with two outs in the ninth to beat Philadelphia closer Jonathan Papelbon, the Mets scored three times off a wild Marmol. But with runners at first and second, Lucas Duda hit a liner up the middle that Marmol speared and flipped to first for the final out.
Reed Johnson led off the game with a homer, had four hits of Chicago's season-high 18 and scored three runs. Rizzo, the Cubs' most hyped prospect this season, singled in the eighth for the first four-hit game of his big league career.
Rizzo and Wood were both acquired in trades before the season by new Cubs president of baseball operations Theo Epstein and general manager Jed Hoyer.
The Cubs, whose 32-51 record is half a game from the NL cellar, could trade Marmol, who lost his closing job once already earlier this season and has been no stranger to shaky outings. He has 28 walks in 25 2/3 innings, though he has been better recently than he was to start the season.
The same could be said of the Cubs, who are 7-3 since Rizzo was called up June 26 -- in a game against the Mets.
"For 10 games, he's been pretty good," Cubs manager Dale Sveum said. "To sit on pitches like he does, and have an educated guess like he does, is impressive."
Rizzo and Jeff Baker each homered in a five-run fifth inning that made it 7-2. The Cubs held on to win for the eighth time in 11 games and sent the Mets to their third loss in nine games.
"It was awesome, right from Reed Johnson's home run," Rizzo said. "And it carried over. Hitting is contagious no matter where you are."
Wood (4-3) allowed two earned runs and was removed after walking pinch-hitter Jordany Valdespin to start the seventh.
"I don't think he had the stuff he's had the last few," Sveum said. "He definitely didn't have the stuff he's had in the past."
Pinch-hitter Ike Davis followed with a single, bringing up Duda. Marmol's quick reflexes saved the Cubs.
In the fifth, Santana fell awkwardly while trying to cover first base on an infield grounder by Johnson. Preparing to take the throw from first baseman Justin Turner, Santana reached out with his foot and apparently got stepped on, then couldn't handle the toss with his bare hand and fell on his side. He took two warmup pitches and remained in the game, but gave up two homers and four more singles after that.
"Obviously, command of his fastball went awry," Mets manager Terry Collins said. "He said it wasn't his foot. He told me afterward his foot was fine. He just didn't make his pitches after that."
Santana (6-5) left after Luis Valbuena's RBI single. Valbuena was thrown out trying to take second and Wood was coming to the plate with two outs, but Collins pulled him anyway.
Johnson's grounder to start the fifth was ruled a single, and Santana allowed another single to Darwin Barney before Rizzo's drive. One out later, Baker hit a solo shot and then Geovany Soto, Joe Mather and Valbuena singled.
The Mets went ahead 2-1 on Duda's solo homer in the second and Ronny Cedeno's RBI double in the third.
Mike Nickeas added a sacrifice fly in the sixth for an unearned run against Wood. Alfonso Soriano tacked on a run with a bases-loaded bloop single in the eighth to make it 8-3. Turner hit an RBI single in the eighth for his fourth hit of the game.
Sveum says RHP Ryan Dempster will start Sunday, and be limited to 70-80 pitches. The right-hander is on the DL because of a tight back muscle. ... Cubs SS Starlin Castro did not start for the first time this season. Sveum said he wanted to watch the game and discuss scenarios with the young star, who has been prone to mental gaffes in the field. ... Johnson's last leadoff homer also came off Santana -- July 23, 2007, when Johnson played for the Blue Jays and Santana for the Twins. ... Collins said OF Jason Bay would take batting practice, run, and do "some defensive stuff" as he tries to come back from his second concussion. He also missed six weeks this season with a broken rib, and is hitting .187 with four HRs and six RBIs in 22 games this season. ... New York wore blue jerseys trimmed in orange with "Los Mets" on the front, a rare departure from the home whites this season. ... Santana last allowed 13 hits on July 28, 2010 against St. Louis. ... Rizzo has reached base safely in all 10 Cubs games he's played in this season.