Wei-Yin Chen improved his record to 9-3, allowing three runs over 5 2/3 innings as the Orioles won by a 4-3 margin over the Nationals on Thursday. Chen narrowly outpitched Gio Gonzalez and received just enough run support to eke out the victory. The lefty yielded eight hits without a walk while striking out six. Chen will go into the All-Star break carrying a 4.15 ERA, a 1.31 WHIP, and a 75/18 K/BB ratio.