Cubs play host to Cardinals at Wrigley Field Thursday.

CHICAGO (AP) — The Cubs made Jon Lester's job easier by staking him to an early lead.

Lester was dominant through six innings of two-hit ball in his 100th start with the Cubs, Jason Heyward hit a two-run homer and Chicago defeated the St. Louis Cardinals 8-5 on Thursday.

Kris Bryant and Kyle Schwarber each had two RBIs as Chicago took a 6-1 lead after two innings.

Every Cubs starter had a hit, including three by Anthony Rizzo and two each by Heyward, Schwarber and Javier Baez.

Heyward's homer and a triple by Javier Baez were the only extra-base hits as Chicago sprayed 12 singles around Wrigley Field.

Lester (2-0) didn't allow a hit until Jedd Gyorko lined a single to left with one out in the fifth.

The left-hander gave a first-inning unearned run, struck out seven and walked one.

Brandon Morrow pitched a perfect ninth to complete a five-hitter and remain perfect in three save chances.

Ten of Chicago's first 16 batters reached against Luke Weaver (2-1), who allowed six runs and nine hits in four innings.

He had yielded only four runs over 17 1/3 innings in three previous starts.

Harrison Bader was hit by a pitch in the first, stole second, advanced to third on catcher Willson Contreras's throwing error and scored on Lester's wild pitch to Marcell Ozuna.

Baez was moved up to second in the batting order by Cubs manager Joe Maddon, and Baez tripled in a bottom half of the first that included RBI singles by Bryant and Schwarber.

The Cubs opened a 6-1 lead in the second when Albert Almora Jr., Rizzo and Schwarber had RBI singles, and Bryant hit a sacrifice fly.

Heyward's fifth-inning homer against Matt Bowman made it 8-1.

Eddie Butler walked Paul DeJong with the bases-loaded in a fourrun seventh, and Steve Cishek forced in a run when he hit pinch-hitter Kolten Wong with a pitch. Dexter Fowler hit into a run-scoring forceout, and another run scored when Baez's throw from second to first trying for a double play was wide for an error.