LeMahieu extended his hitting streak to 18 games with an RBI double as part of a four-run first, tripled in the fifth and singled in the ninth to help Colorado won for the third time in five games.
Daniel Descalso, who started at shortstop in this game, made a leaping grab of a line drive by Kris Bryant to end the seventh inning and strand two runners.
Nolan Arenado had a two-run double and Nick Hundley added a run-scoring groundout in the first against Dallas Beeler (0-1).
Yohan Flande (1-1) got his first career victory, giving up a run and four hits while walking three and striking out four in five innings.