Nationals 6, Mets 4: Michael Morse belted his third career grand slam and rookie Bryce Harper launched a two-run homer as host Washington collected its 11th win in 13 games.

After retiring the first nine batters he faced, Johan Santana (6-9) ran into trouble in the fourth inning. The veteran left-hander allowed three hard-hit singles before Morse deposited a high fastball into the seats in right field to extend his hitting streak to 13 games.

Harper gave Washington a 6-2 lead with a two-out homer in the fifth inning. The rookie's 11th blast extended Santana's franchise record of allowing at least six earned runs in five consecutive starts. Santana fell to 3-7 since recording New York's first no-hitter in franchise history.

Ross Detwiler (7-5) benefited from the offensive explosion to pick up the victory. Detwiler overcame Daniel Murphy's two-out single in the first inning to toss six solid frames.

Two relievers bridged the gap to Tyler Clippard, who struck out a pair in the ninth inning for his 26th save.

Scott Hairston ripped three doubles and scored twice while Kelly Shoppach belted his first homer as a member of the Mets, who fell for the eighth time in 11 outings.

GAME NOTEBOOK: Morse's grand slam was the first this season by the Nationals. He had been 0-for-9 in his career versus Santana prior to the blast. ... Nationals All-Star SS Ian Desmond returned from his stint on the disabled list with a torn left oblique and went 0-for-4. ... Washington improved to 10-3 against New York this season.