It's the second straight season Schwarber has reached 20 homers. He hit a career-high 30 last year for the Cubs. He also joins Javier Baez, who leads the team with 23 homers.
Anthony Rizzo got in on the action, too, as he outdid Schwarber, hitting his 17th homer 444 feet to center as part of a five-run inning. Schwarber's home run traveled 405 feet to right.
Lockett was making a spot start for Joey Lucchesi, who was sidelined with a stomach bug.
Rizzo now has 182 home runs with the Cubs and and moved into sole possession of 11th on the team's all-time list, passing Alfonso Soriano (181). Next up is Hack Wilson, who hit 190 home runs for the team.