Willingham's eighth-inning homer narrowed Baltimore's lead to 4-3. Anderson Hernandez tied it in the bottom of the ninth with an RBI triple and scored the winning run on a throwing error by second baseman Justin Turner.

Martis started for the Nationals, allowing two runs and two hits with a walk. The 21-year-old right-hander is on the short list to fill one of two spots still open in Washington's rotation.

"He kept the ball down," manager Manny Acta said. "He struggled a little bit with his breaking ball, but he was able to throw that changeup over the plate and got himself stretched out very well, the way we were expecting him to."

Alfredo Simon started for the Orioles, going four innings. He struck out three while allowing a hit and a walk.

Simon, a 28-year-old right-hander, is one of 10 pitchers vying for three open spots in Baltimore's rotation.

"He's got power stuff," manager Dave Trembley said. "He's a horse. He's a big guy and he keeps going right at you. He had a nice outing today."

Nolan Reimold was 2-for-3 with a two-run homer and a walk, and Robby Hammock added a two-run double for the Orioles.

Jesus Colome got the win, pitching a scoreless ninth inning.

Wilfrido Perez took the loss.

Notes: Nationals catcher Wil Nieves is day to day with a bruised right hand. He was hit by Dennis Sarfate's pitch in the fifth. Sarfate plunked Brad Eldred earlier in the inning. ... Washington reassigned left-hander Gustavo Chacin, infielders Brad Eldred and Pete Orr, and outfielder Ryan Langerhans to minor league camp. The Nationals also optioned catcher Luke Montz and outfielder Roger Bernadina to Triple-A Syracuse.