WASHINGTON -- Jayson Werth entered Washington's eighth game of the season with zero homers and a grand total of one RBI.
Bryce Harper? He also came into Wednesday without a long ball and hadn't driven in a run. He was hitting .160, had nearly three times as many strikeouts as hits and was dropped to seventh in the batting order.
They both got going in a hurry. Werth delivered a go-ahead grand slam in the eighth inning off Carlos Marmol after Harper's upper-deck, three-run homer started a comeback from an early deficit, and the Nationals beat the Miami Marlins 10-7 on Wednesday night.
"Crazy game. Back and forth," said Werth, who violently tossed his bat after making contact on his homer. "One of those games where you play that long, you want to win."
Helped by 3 1/3 innings from Craig Stammen after Jordan Zimmermann produced his shortest start in the majors, Washington overcame deficits of 5-0 and 7-6. Werth's shot off Marmol (0-1) came with one out, after the reliever allowed a single, hit a batter, then intentionally walked Anthony Rendon to load the bases.
"Knowing Jayson, if the pitcher looks at him wrong, he'll take that personally," Stammen said. "So them blatantly walking to get to him -- typically they don't walk to get to your 3-hole hitter, especially a veteran guy that's proven he can get big hits. But they chose to, and it worked out in our favor this time."
Explained Marlins manager Mike Redmond: "We were trying to win the ballgame there. We were trying to get a ground ball," hoping Werth might hit into a double play to end the inning.
But Werth helped make a winner of Tyler Clippard (1-1), who yielded Garrett Jones' tiebreaking RBI double in the top of the eighth after walking a pair of batters. Rafael Soriano, Washington's sixth pitcher, worked the ninth for his second save.
Jones' hit put Miami ahead 7-6, but Giancarlo Stanton was thrown out at the plate on Rendon's relay of Werth's throw from right on the play.
Werth then came through with his fourth career grand slam, and first with the Nationals. He drove an 0-1 pitch into the visitor's bullpen in left-center, then acknowledged the fans' cheering with a curtain call.
"I was trying to go in and get a ground ball. That's what I'm trying to do," Marmol said. "The ball stayed a little in the middle and he hit it good."
Werth was responsible for five RBI on Wednesday, including on a groundout in the fifth after Rendon's triple to pull the hosts within 5-4.
The comeback had started when Harper, the 2012 NL Rookie of the Year, had a successful 10-pitch at-bat -- including five consecutive fouls -- against left-hander Brad Hand in the fourth inning. Harper turned on a 94 mph offering and hit it over the foul pole and into the fifth row of the third deck beyond right field.
That last pitch, Hand said, "kind of went down and in, right into his happy zone."
Harper's home run trimmed what had been a five-run Marlins lead to 5-3.
"Completely different down two, as opposed to down five," Nationals manager Matt Williams said. "That's a big swing for him, confidence-wise. It's a big swing for us."
Zimmermann, who won 19 games last season, left after allowing five runs in 1 2/3 innings. Derek Dietrich was awarded a two-run homer after a replay review in the second inning, and Christian Yelich wound up with three hits and two walks.
"Just wasn't crisp tonight with his command," Williams said about Zimmermann.
But the Marlins allowed the Nationals to rally, helping the hosts by making three errors, raising Miami's total to 11 through nine games.
Washington improved to 6-2, and it has trailed in four of those victories.
"I never felt out of this game," Werth said, "that's for sure."
Zimmermann's previous shortest outing was two innings, on July 21, 2013, against the Dodgers. ... Washington 3B Ryan Zimmerman returned to the starting lineup for the first time since Saturday after sitting out with a sore throwing shoulder. ... Marlins RHP Arquimedes Caminero threw 1 2/3 hitless innings. He was recalled from Triple-A New Orleans before the game to replace RHP Jacob Turner, who went on the 15-day DL with a strained right shoulder.