Pirates 4, Nationals 3: Pedro Alvarez hit a two-run homer and Charlie Morton snapped a 14-start winless streak as host Pittsburgh held off Washington for the second straight night.

Ike Davis added two hits and scored twice for the Pirates, who have won three straight and four of five. Morton (1-6) gave up one run on five hits over 5 2/3 innings and the bullpen survived a couple of rocky frames before Jason Grilli worked around a leadoff walk in the ninth for his fifth save, getting the final two outs on fly balls to the warning track.

Denard Span had two hits and Greg Dobbs and Scott Hairston added sacrifice flies for the Nationals, who have dropped three straight and four of five. Jordan Zimmermann (3-2) allowed four runs on seven hits over six frames to take the loss.

The Pirates got to Zimmermann in the second inning as Davis led off with a single, Russell Martin roped a double to left and the pair came home on Starling Marte's RBI groundout and a wild pitch. Alvarez doubled the advantage in the fourth, belting a 1-0 changeup into the shrubs in center for his ninth homer.

The Nationals loaded the bases with no outs in the sixth, but pushed across only one run on Dobbs' sacrifice fly before Jared Hughes came on in relief of Morton and got out of the jam. Washington pushed across two in the eighth on a sacrifice fly and a passed ball before Span grounded back to pitcher Bryan Morris to end the threat.

GAME NOTEBOOK: The Pirates activated closer Grilli from the disabled list before the game and optioned C Tony Sanchez to Triple-A Indianapolis. Grilli had been on the DL since April 26 with a strained left oblique. … The Nationals snapped an 0-for-25 skid with runners in scoring position with Zach Walters' single to load the bases in the eighth. … Pirates SS Clint Barmes recorded his first stolen base since Sept. 18, 2011, when he was with Houston.