Curtis Granderson opened a five-run eighth inning with his 300th homer, a tiebreaking shot that helped the Mets bail out an ailing Harvey in a 9-4 victory Wednesday over the Chicago Cubs.
Matt Harvey lost the zip on his fastball and gave up three homers in four innings - including Anthony Rizzo's latest leadoff shot and a titanic drive by Kyle Schwarber.
New York also lost second baseman Neil Walker to a left leg injury , the latest issue to befall a team hampered by a long list of health problems the past two seasons. But replacement Lucas Duda hit a three-run homer off Hector Rondon in the eighth, and T.J. Rivera capped the outburst with an RBI single for his third hit.
With sluggers Yoenis Cespedes and Michael Conforto on the bench to begin the game, the resurgent Mets came back from a 4-1 deficit and took two of three from the World Series champions heading into a pivotal four-game series against NL East-leading Washington. New York (30-34) has won five of six overall.
Jerry Blevins (4-0) struck out three of his four batters, and Addison Reed retired Rizzo with the bases loaded for the final out.
Juan Lagares hit a tying triple on an 0-2 pitch from Pedro Strop with two outs in the sixth, the start of a meltdown by Chicago's bullpen.
The Cubs (32-33) hit back-to-back homers to begin the game but played some sloppy defense and lost for the eighth time in their past nine visits to Citi Field, including the 2015 NL Championship Series.
Cubs rookie Ian Happ, who hit a grand slam Tuesday night, followed Rizzo's leadoff shot with his seventh home run and Chicago had a 2-0 lead after seven pitches. Schwarber's 467-foot shot over the Shea Bridge, a walkway for Citi Field fans above and beyond the bullpens in right-center, made it 4-1 in the fourth.
With the bases loaded in the fourth and the Mets short on the bench, Collins sent up pitcher Steven Matz to pinch hit for Harvey. Matz legged out an RBI infield single off starter Mike Montgomery, and Lagares trimmed it to 4-3 with a sacrifice fly.
Chicago has dropped six of eight following a five-game winning streak.
The Cubs begin a three-game series Friday night in Pittsburgh with RHP Eddie Butler (3-2, 4.03 ERA) on the mound against Pirates rookie RHP Trevor Williams (3-3, 5.13).