KISSIMMEE, Fla. – Bryce Harper had a single in his first start for the Washington Nationals but Chris Johnson hit a two-run homer that led the Houston Astros to a 3-1 victory Saturday.

Harper, the 19-year-old outfielder who was drafted first overall in 2010, went 1 for 3 with a hit off Astros starter Livan Hernandez in the Grapefruit League opener for both teams.

Free agent signee Edwin Jackson pitched two scoreless innings for the Nationals.

Johnson, competing for Houston’s third base job after a disappointing 2011 season, hit a drive over the center field fence off Ross Detwiler in the fourth inning.

Catcher Jason Castro, who missed the entire 2011 season with a knee injury, played the first three innings for Houston.

(Copyright 2012 by The Associated Press. All Rights Reserved.)