Three batters later, Wilson Ramos hit a monster three-run homer that went completely out of the stadium in left field.
But the Astros would make it a one-run game by the fifth inning. With Tanner Roark on the mound, Marc Krauss put Houston on the board with a solo home run in the third. Krauss went 3-for-4 with two runs on the afternoon.
An inning later, the Astros scored two unearned runs off Christian Garcia. George Springer reached base on a three-base error by Span in center field. Springer then scored on a sacrifice fly by Marwin Gonzalez. Carlos Corporan came across with the Astros' third run on a single by Robbie Grossman.
Reliever Rafael Soriano, appearing in his first game of the spring, allowed a two-run double to Corporan to make it a 6-5 game in the fifth.
Zach Walters would give the Nationals a three-run cushion by hitting a Josh Zeid pitch to left field for a single, scoring Will Rhymes and Jeff Kobernus. The runs were charged to right-hander Eric Williams.
Oberholtzer went two innings, with five of the six runs earned, while Roark gave up four hits and one run with three strikeouts over 2 2/3 innings.
Up next: The Astros will divide the team Saturday for a pair of games at 12:05 p.m. CT on MLB.TV. Manager Bo Porter will stay to watch the Astros, with Jarred Cosart on the mound, face the Yankees at Osceola County Stadium. Bench coach Dave Trembley will manage the Astros in Clearwater to face the Phillies, with Dallas Keuchel getting the start. In both games, instant replay will be used.
Bill Ladson is a reporter for MLB.com and writes an MLBlog, All Nats All the time. He also could be found on Twitter @WashingNats. This story was not subject to the approval of Major League Baseball or its clubs.