Dansby Swanson hit two homers Wednesday afternoon, including a tiebreaking three-run shot and a grand slam, as the visiting Chicago Cubs beat the New York Mets 10-3 in the first game of a day-night doubleheader.

Michael Busch hit a game-tying two-run homer in the fifth for the Cubs, who earned their fourth win in five -- a span in which they outscored the Mets, Colorado Rockies and Toronto Blue Jays 49-25.

Michael Conforto began Chicago's comeback from a 3-0 deficit with an RBI double immediately before Busch's homer. Swanson put the Cubs ahead by homering off Mets starter Nolan McLean (4-5) in the sixth before his grand slam off right-hander Jonathan Pintaro in the eighth.

It was the second career seven-RBI game for Swanson, the other coming on July 31, 2021, when he was playing for the Atlanta Braves against the Milwaukee Brewers.

Javier Assad (6-1) gave up three runs on five hits and two walks while striking out five over five innings. A trio of relievers blanked the Mets on two hits over the final four frames.

Jared Young and Francisco Alvarez hit back-to-back fourth-inning homers for the Mets, who took their fourth straight loss. Alvarez and Carson Benge had two hits apiece.

McLean allowed six runs on seven hits and two walks while striking out nine over six innings.

The teams combined to strand five runners in scoring position in the first 3 1/2 innings before the Mets took a 3-0 lead in a span of five pitches to open the bottom of the fourth, when Bo Bichette singled ahead of the homers by Young and Alvarez.

McLean struck out the first two batters in the fifth before the Cubs tied the score in a four-pitch span. Pete Crow-Armstrong singled and raced home on Conforto's hit, after which Busch homered to right.

McLean was one out away from escaping a one-out jam in the sixth after Nico Hoerner doubled. However, the right-hander gave up a single to Miguel Amaya, and Swanson followed with his first homer of the game.

Pintaro loaded the bases via two walks and a hit batter in the eighth to set up Swanson's grand slam.