Dansby Swanson hit a tiebreaking three-run homer in the sixth inning and added a grand slam in the eighth inning, lifting the Chicago Cubs to a 10-3 win over the reeling New York Mets in the opener of a day-night doubleheader. The Cubs trailed 3-0 before tying the game in the fifth inning, when Pete Crow-Armstrong singled with two outs against Nolan McLean and scored on Michael Conforto’s double before Michael Busch hit a two-run homer off the advertising signage in right field. Swanson, the Cubs’ No. 9 hitter, launched a two-out, 400-foot homer beyond the left-center field fence before hitting a grand slam two innings later.