WASHINGTON -- Mat Latos stood on the mound, surrounded by his infielders, manager Dusty Baker and athletic trainer Paul Lessard in the top of the fifth inning.

The right-handed pitcher, who had hit his fourth career homer in the second inning, was two outs away from being in line for a victory in the first start with his new team.

But Latos, with a seven-run lead, limped off the mound with a right hamstring injury after going 4 1/3 innings in a spot start. The Nationals bullpen, however, gave up just two hits the rest of the way as Washington beat the New York Mets 8-1.

"I feel great. I had command of my off-speed pitches," said Latos, a native of nearby Alexandria, Va. "I wish I could have gone more innings for the bullpen. It is unfortunate that (the injury) happened."

Latos, who was released earlier this season by the Chicago White Sox, pitched for then-manager Baker with the Cincinnati Reds in 2012 and 2013. Latos said he will deal with his injury day-to-day and rely on the medical staff.

"He has been in the pressure cooker with me," said Baker, the first-year Washington manager. "He wasn't throwing that hard in Chicago. We gave him another chance."

The Mets also gave Washington third baseman Anthony Rendon another chance to come through batting back of Bryce Harper.

After striking out in the first inning, Rendon hit a three-run homer in the second after Mets manager Terry Collins called on Mets pitcher Rafael Montero to give Harper an intentional walk with two outs. It was the 18th homer of the season for Rendon, who is trying to reach 20 and join five other teammates in that club.

The first-place Nationals (86-58) now lead the second-place Mets (76-68) by 10 games in the division.

Washington has won eight of its last 11 and is a season-high 28 games above .500. New York is 16-6 in the last 22 games and still in the National League Wild Card hunt after giving up three hits to old friend Daniel Murphy.

Rendon, who went deep during a four-run second inning, is hitting nearly .320 in his last 45 games.

Harper walked three times and scored twice. Former Mets second baseman Murphy, now batting .347, had two doubles to give him 44 this year, the most in the league. Trea Turner also had two hits for Washington.

The losing pitcher was Mets starter Montero (0-1), who did not get out of the second inning as he allowed six runs and now has a 8.10 ERA in five appearances this year.

"It is frustrating because he has good stuff. This is the big leagues," Collins said. "Tonight was certainly a downer."

The winner was Nationals rookie Reynaldo Lopez (2-4), who pitched three scoreless innings while giving up no hits and two walks. It was the first bullpen outing for Lopez after six starts.

"I thought he handled it well," Baker said. "He had some great changeups."

Jose Reyes and Travis d'Arnaud had two hits for the Mets, who won the National League East title last year and Washington captured the championship in 2014.

Montero made his third start of the season.

"We will make a switch," Collins said of taking Montero out of the rotation.

New York took a 1-0 lead in the first as Reyes led off with a double and later scored on a sacrifice fly by Yoenis Cespedes.

But the Nationals grabbed a 2-1 lead in the last of the first as Montero walked Harper and Ramos with the bases loaded to force in runs.

A single to left by Murphy in the first to load the bases gave him a hit in all 17 games against the Mets this year.

Latos led off the bottom of the second with a solo homer to left to make it 3-1.

Later in the inning, Harper was walked intentionally to put runners on first and second with two outs. Rendon followed with a majestic three-run homer to left to give the Nationals a 6-1 lead and send Montero to the showers in favor of Gabriel Ynoa.

Ramos and Ryan Zimmerman had RBI singles in the fourth to make it 8-1.

Latos was 6-2 with the Chicago White Sox before he was signed by the Nationals as a minor league free agent on June 30.

"That was big for us to win that game," Baker said. "We had (Montero) on the ropes in the first. That was a big three-run homer by Rendon."

NOTES: Washington RHP A.J. Cole (1-2, 4.56 ERA) will start Tuesday against Mets RHP Noah Syndergaard (13-8, 2.48) in the second game of the series. ... Washington INF Daniel Murphy played for seven seasons for the New York Mets and hit seven postseason home runs in 2015 for New York. ... Mets INF Asdrubal Cabrera hit .229 in 49 games for the Nationals in 2014. ... Mets LHP Jerry Blevins pitched in 64 games for the Nationals in 2014 and was traded to the Mets at the end of spring training in 2015. ... Washington RHP Mat Latos, theMonday starter, won 14 games in both 2012 and 2013 while pitching for manager Dusty Baker in Cincinnati. Baker is the first-year skipper of the Nationals. ... Mets RHP Rafael Montero made eight starts for the Mets in 2014 and one in 2015. He made his 12th MLB start on Monday in his 20th career outing.