Cubs right-hander Tyler Chatwood left in the third inning with right elbow discomfort. Colin Rea, José Quintana (1-0), Ryan Tepera, Kyle Ryan and Duane Underwood Jr. then combined for 6 2/3 innings of two-hit ball.

Chatwood was making his second start since returning from the IL on Aug. 25. He had been sidelined with a lower back strain.

Castillo, a National League All-Star last season while going 14-8, had allowed one homer all season before surrendering three against the Cubs. He struck out seven and walked one.

“It was two pitches I didn’t locate well,” Castillo said about Chicago’s two fourth-inning homers. ” I think last year we threw a lot of the changeups and the batters saw a lot of it. That is why I’m working so hard on the slider.”

The Cubs also displayed flashy defense with three diving catches, including second baseman Nico Hoerner’s grab of Nick Castellanos’ low liner with the bases loaded to end the seventh. Happ and Heyward each made a diving catch in the outfield.

For the third straight day, both teams wore their No. 42 jerseys they originally wore on Friday to help celebrate Jackie Robinson Day. It also was a nod to MLB paying tribute on Sunday to the 100th anniversary of the launch of the Negro Leagues. Cutouts of Negro League players were perched in seats behind the plate.