NEW YORK — DJ Stewart hit a tiebreaking three-run homer in the sixth inning Tuesday night, lifting the New York Mets to a 4-2 win over the Chicago Cubs.

Stewart, whose roster spot could have been in jeopardy with the activation of J.D. Martinez last week and the return Tuesday of Starling Marte from the bereavement list, had just three hits in his previous 23 at-bats before homering into the second deck in right field against Adbert Alzolay (1-3) to give New York a 4-1 lead.

Stewart gazed toward the home dugout before flipping his bat like a baton upon beginning his trot.

Sean Reid-Foley (1-0) tossed a hitless sixth. Jorge López earned his second save after giving up a run in the ninth, when Mike Tauchman doubled and scored on a groundout by pinch-hitter Matt Mervis.

Pete Alonso had a sacrifice fly in the first for the Mets before Miguel Amaya tied the score with a sacrifice fly in the second.

Mets starter Sean Manaea and Cubs counterpart Javier Assad each allowed one run in five innings. The teams were hitless in six plate appearances with runners in scoring position against the starters.

Cubs pitcher Shota Imanaga (4-0, 0.98 ERA) looks to continue the historic start to his career Wednesday night, when he opposes the Mets José Buttó (0-1, 2.86) in the third game of the four-game series. Imanaga is the first pitcher since 1901 to open his career 4-0 with a sub-1.00 ERA and at least 28 strikeouts in his first five starts.