Andrew Stevenson’s two-run single in the fourth got Washington within 3-2 before Miami responded with RBI singles from Corey Dickerson and Wallach in the bottom of the inning.

The Marlins padded their lead with an RBI single from Jesus Aguilar in the fifth and Cooper’s run-scoring double in the sixth.

Richard Bleier retired the four batters he faced to set up Brandon Kintzler, who pitched a scoreless ninth.

Corbin was lifted after six innings. The left-hander allowed seven runs and struck out seven.

“One of those days, it wasn’t very good,” Corbin said. “They came out swinging, they didn’t miss any of my mistakes, they came to hit it.”

The loss dropped the Nationals to 19-31 — the same record before their 74-38 finish and eventual run to a World Series championship last season.

“I’d rather be 31-19, but hey, we just gotta keep battling, we gotta keep it going for the next 10 games or whatever it is and just try to go 1-0 (Sunday),” Washington manager Dave Martinez said . “That’s where we’re at right now.”

LOPEZ OVERCOMES DIFFICULT FOURTH:

After enduring a 22-pitch fourth inning, Lopez rebounded in the fifth, when he retired Victor Robles on a flyout to center and struck out Trea Turner and Juan Soto. Lopez limited the Nationals to the two-run fourth after Carter Kieboom was thrown out at home on an attempted double steal for the third out.