Dunn, Zimmerman homer in Nats’ 8-4 win

PITTSBURGH — Adam Dunn and Ryan Zimmerman homered and the Washington Nationals rallied from a three-run deficit for an 8-4 victory over the Pittsburgh Pirates on Monday night.

Cristian Guzman had two hits and two RBIs and Tyler Clippard (2-1) earned the win with three hitless innings of relief for Washington, which won the last two games to split the four-game series between the last-place teams.

Andrew McCutchen homered for the fourth time in three games and Ryan Doumit went 3 for 5 for the Pirates, who have lost seven of nine.

Mike MacDougal earned his eighth save by getting Delwyn Young, the only batter he faced, to ground out with two runners on.

The Pirates took a 3-0 lead in the first and had 12 baserunners through the first five innings while the Nationals only advanced one runner past first base in that span against Charlie Morton.

In the sixth, Dunn hit a 2-1 pitch from Morton just inside the foul pole in left about six rows back for a three-run homer, his 27th of the season, that gave the Nationals a 4-3 lead.

Morton (2-4) allowed all four of his runs and four of his six hits in the sixth.

Pittsburgh’s Jeff Karstens struck out the first two hitters of the seventh but allowed the next six hitters to reach base with four of them scoring. Guzman had an RBI triple, Zimmerman hit a two-run homer, his 21st, and Elijah Dukes added an RBI single to make it 8-3.

For the second time in three days, McCutchen led off the bottom of the first with a home run. On Saturday, McCutchen became the only rookie in Pirates history to hit three homers in a game.

Steve Pearce had an RBI single and Young had a run-scoring fielder’s choice in the first for Pittsburgh.

Starter Garrett Mock walked two and allowed a single to Doumit to open the fifth but Clippard got Young to ground into a comebacker double play and Andy LaRoche to pop out to short.

Making his fourth start of the season and seventh of his career, Mock was charged with three runs — two earned — seven hits and four walks in four-plus innings.

NOTES: Doumit, the Pirates’ cleanup hitter, drove in a run with a double in the ninth, his second RBI since July 23. … Dunn went 3 for 4 — a triple short of the cycle — for his fifth three-hit game of the season. … Guzman has at least two hits and an RBI in nine of his past 10 games. He has a 10-game hitting streak. … Washington committed three errors.