WASHINGTON -- Ryan Zimmerman rounded first base with his arms extended at his side, a pose that has become all too familiar for the man they call Mr. Walk-Off around D.C., before he suddenly had to break into a sprint toward second base. There, he stood and waited for a crew chief review to overturn what he knew right away out of the batter's box.

Zimmerman hit his 11th career walk-off home run and first since 2015 in the ninth inning Wednesday night, leading the Nats to an 8-7 come from behind victory over the Phillies at Nationals Park. The homer off Phillies right-hander Seranthony Dominguez moves Zimmerman into a tie with David Ortiz and Tony Perez for the eighth-most walk-off home runs in MLB history and ties Perez for the second most in National League history. Only Jose Pujols (12) has more walk-off homers than Zimmerman among active players.

It provided a feel-good victory for the Nats, still 7 1/2 games back in the NL East, but who have now won back-to-back games over their division rival and will go for a sweep on Thursday.

• Most career walk-off home runs in MLB history

"You can't try to do too much. The second you try to do stuff like that, it doesn't happen," Zimmerman said. "Those guys are supposed to get you out. That guy's nasty ... in the ninth inning in a close game and the other team has the lead, those guys are usually pretty good. So I think that kind of put the pressure all on them. They're supposed to get me out."

The ninth inning was extended thanks to Juan Soto, who ripped a double down the right-field line with two outs and two strikes to bring Zimmerman to bat. Then, Dominguez left a 2-1 fastball over the middle of the plate, which Zimmerman launched over the right-field wall. Once the call was overturned, Zimmerman's hands shot up into the sky before he began racing around the bases and waving off an overzealous Soto, who had already scored the tying run on the home run, but was running toward Zimmerman as he rounded the bases.

The Nats were worried that if Soto touched Zimmerman on the basepaths then Zimmerman would have been ruled out.

"I was screaming bloody murder," manager Dave Martinez said.

"I just ran around and Zim was like, 'Get away,'" Soto said with a laugh. "And I was like, 'What are you talking about?' Then I turn around and see everybody at home plate and said, 'Dang, I have to be there.'"

Zimmerman's homer helped the Nats come away with a victory despite a rocky return from Stephen Strasburg, who struck out five and walked one, but allowed five runs on seven hits in four innings and displayed a declining fastball that caused some concern. However, Strasburg believed his lack of endurance after making just one start in the past two months was the cause for the decline in velocity, which dipped into the low 90s in the fourth inning.

"I saw it too, so I'd like to think that it's … I don't know if it's rust, I think it's just endurance," he said. "Hopefully that's what it is."

Zimmerman's heroics allowed the Nats to finish the game on a high note and win their second straight game after trading away two of their best hitters on Tuesday. As one of the leaders in the clubhouse, Zimmerman was adamant after the trades that the Nats would not quit during the final weeks of the season. His home run Wednesday helped ensure that.

"He always competes and never gives up," Soto said. "That's what I probably love [about] him and I'm here with him. If he never gives up, I don't."

MITEL REPLAY OF THE DAY

Both Zimmerman and the entire Nationals dugout believed the ball had cleared the fence, but Zimmerman stopped at second base to wait for the crew chief review. Eventually, the call on the field was overturned, and the Nats emerged from the dugout to greet Zimmerman at home plate with a celebratory shower.

"There's a space behind that wall, I've hit a lot of balls to that terrible triangle up there," Zimmerman said. "Once I saw it, I was pretty sure they were going to overturn it."

SOUND SMART

Bryce Harper collected three hits, scored a pair of runs, drove in a run and stole a base Wednesday, continuing his hot streak since the All-Star break. He is batting .364 with seven home runs, 27 RBIs and 23 runs scored in the 30 games since the break.

UP NEXT

A pair of National League Cy Young Award candidates will face off in Thursday's series finale at 1:05 p.m. ET when Max Scherzer of the Nationals matches up against Aaron Nola of the Phillies. Scherzer, perhaps the favorite to capture his third straight NL Cy Young Award, has made just one start against Philadelphia this year, when he struck out a season-high 15 batters on May 6 in 6 1/3 innings of one-run ball.