NEW YORK -- Jacob deGrom struck out 12 and carried a perfect game into the sixth inning of his second start all season, pitching the New York Mets past the Atlanta Braves 5-2 on Sunday for their 12th victory in 14 games.

Pete Alonso drove in two runs, and the first-place Mets finished with 19 strikeouts, including three in a row from closer Edwin Diaz to end it. They took four of five from Atlanta in their National League East showdown, extending their division lead to 6½ games over the defending World Series champions.

Pitching at home for the first time in 13 months, a dominant deGrom (1-0) retired his first 17 batters -- 12 on strikeouts -- before walking Ehire Adrianza with two outs in the sixth.

"Stepping out there was a little emotional," deGrom said. "I took a second, tried to take it all in, and then tried to focus and try to take care of business."

Dansby Swanson followed with a two-run homer on the 76th and final pitch from deGrom, making it 5-2.

"I just feel bad for whoever has to face him," Mets outfielder Brandon Nimmo said in his postgame interview on the field. "He's throwing 101, 102 [mph] out there, and he's locating everything. Hats off to him for getting healthy and getting back to us. He's primed and ready to go."

The two-time Cy Young Award winner missed the final three months last season with right forearm tightness and a sprained elbow, and he was then shut down late in spring training because of a stress reaction in his right scapula. He finally returned Tuesday at the Washington Nationals, throwing five innings of one-run ball in a rare Mets loss lately.

"Throughout this whole time, the process has been very slow, and I was trying not to do too much, but I felt good the whole time," deGrom said of his road back to the majors. "I think I was able to take a step back and take a look at where I was mechanically ... try to put myself in a better position to stay healthy."

Mets fans had to wait a little longer than they planned to see deGrom go to work, as the start of the game was delayed 20 minutes by rain. Once play began, however, deGrom didn't disappoint the crowd.

"It's a pick-me-up," Mets manager Buck Showalter said. "The fans have been huge for us. To come out here, as hot as it is, for them to come out and support the team, the guys really fed off of it."

The Associated Press contributed to this report.