Cespedes smacked the long ball on Tuesday at Busch Stadium. He stepped into the box in the top of the fifth inning against Cardinals right-handed pitcher Luke Weaver. The Mets trailed the Cardinals 4-1 with two outs in the frame. Wilmer Flores and Michael Conforto were standing on first and second.
Cespedes worked a 3-1 count against Weaver, drawing the green light for his fifth offering of the at-bat. Weaver then tossed in an 84.3-mph changeup. Cespedes turned on the pitch, pulling it on a line drive to left field. The shot cleared the fence for an estimated 463-foot homer, according to Statcast. The ball left the park at 115.1 mph.
The homer was the Mets' longest since 2015.
"In that at-bat, he was losing the strike zone with the fastball, so I was hoping to catch a changeup," Cespedes told reporters. "Then, I caught it. And I hit it."
Paul Dejong hit an RBI double in the bottom of the inning, giving the Cardinals a 5-4 lead. Adrian Gonzalez brought in Todd Frazier on an RBI double, tying the game in the top of the eighth inning. Jay Bruce brought in the go-ahead run with a solo shot in the top of the tenth inning.
Cespedes went 1-for-5 on the day, with three RBIs, two strikeouts and a run scored. He is now hitting .195 on the season, with five home runs, 21 RBIs and a league-high 39 strikeouts.
"I think that's the day we've been waiting on, to get those guys [Bruce, Cespedes] going," Mets manager Mickey Callaway said. "They came out early today, took early BP [batting practice] on the field ... hit for a very long time. They are out there to win and they got the job done tonight."