WASHINGTON (AP) — Left-hander Mitchell Parker threw seven shutout innings, and Luis Garcia Jr. had three singles and two RBIs and the Washington Nationals beat the Houston Astros 6-0 on Sunday.

The Nationals have won three of their past four series after starting the season 2-6.

After allowing two runs over five innings last Monday in his major league debut, a 6-4 win over the L.A. Dodgers, Parker (2-0) was even more effective in his second major league start, allowing three hits, striking out eight and walking none, throwing 57 of his 73 pitches for strikes.

“He has so much poise,” Nationals manager Dave Martinez said. “He’s ready. He gets the ball, ready to get back on the mound. I watched him today. He threw a ground ball. The play was made and he got right on the mound and was holding his glove up as if, ‘hey, come on, give me the ball, like I’m ready to get back on there’. It was cool to watch. He understands what he wants to do.”