NEW YORK -- Blake Swihart has legs. And the Boston Red Sox catcher knows how -- and when -- to use them.

Swihart stole a base to extend the Red Sox's three-run seventh inning Friday night and hit an inside-the-park home run leading off the 10th to begin a three-run outburst by Boston, which survived a scare in the bottom of the inning and held on for a 6-4 win over the New York Mets at Citi Field.

Swihart's inside-the-park homer -- the first by a Red Sox catcher since Duane Josephson on Sept. 3, 1971 -- should have gone into the books as a traditional round-tripper. Replays showed the ball hit off the orange home run line atop the center-field wall.

"I was close to first, or at least going to second, and I thought it had gotten over because of the way it bounced back," Swihart said.

But umpires never gave the home run signal and Swihart raced around the bases as the ball bounced toward the infield and out of reach of jogging Mets center ielder Juan Lagares.

"Just kept my head down running," Swihart said. "I kind of watched the center fielder run after it. He was kind of jogging after it. I didn't hear anything, so I just kept running."

Lagares finally got to the ball as Swihart rounded third, but the relay from Lagares to shortstop Ruben Tejada to catcher Travis d'Arnaud wasn't nearly in time to get the sliding Swihart.

"I looked at him at first base and he knew what he was trying to do," Red Sox interim manager Torey Lovullo said. "I don't think he planned on an inside-the-park home run. But we run hard until our base coaches stop our guys. He did exactly what he's supposed to do."

The Red Sox added two valuable insurance runs -- via a sacrifice fly by second baseman Josh Rutledge and an RBI single by shortstop Xander Bogaerts -- before holding off the Mets in the bottom of the 10th.

Right-hander Junichi Tazawa allowed a single to second baseman Wilmer Flores before inducing d'Arnaud to hit into a 1-6-3 double play. But Tazawa tweaked his back reaching for the comebacker and was visited by Lovullo and the Red Sox trainers, who let him stay in after he threw two warmup pitches.

But Tazawa, who entered the night with just nine walks in 54 innings this season, walked the next four batters, including right fielder Curtis Granderson with the bases loaded.

Tazawa was pulled for left-hander Craig Breslow, who retired left fielder Yoenis Cespedes on a long fly out to center.

The save was the first of the season for Breslow. Left-hander Tommy Layne (1-1) picked up the win after working around a leadoff walk in the ninth.

Right-hander Carlos Torres (5-6) allowed three runs and four hits in two-thirds of an inning.

Swihart, Bogaerts, first baseman David Ortiz and center fielder Jackie Bradley all had two hits apiece for the Red Sox (59-69), who improved to 9-5 under Lovullo.

Mets right-hander Matt Harvey shut out the Red Sox through six innings before Boston took the lead in the seventh, when Ortiz greeted right-hander Logan Verrett with a home run. With two outs, Swihart singled and stole second. Two pitches later, Bradley homered to center.

"I pride myself on being an athletic catcher," Swihart said. "I have the ability to steal a bag. I don't do it all the time. A lot of the time they want me to save the legs. When those opportunities arise for me to get into scoring position, I'm going to do it."

Flores, Tejada and third baseman David Wright had two hits apiece and d’Arnaud had two RBIs for the Mets (71-57), who had their seven-game winning streak snapped.

New York, which has scored 77 runs in its last eight games, remained 6 1/2 games ahead of the Washington Nationals in the National League East.

"You've got to like your chances the way they've been swinging the bats," Mets manager Terry Collins said of New York's 10th-inning rally. "We just didn’t finish it."

D'Arnaud had an RBI single in the fourth. In the fifth, Wright -- who hadn't played at home since April 14 because of spinal stenosis -- singled with two outs and came around to score when right fielder Rusney Castillo misplayed first baseman Michael Cuddyer's single.

The Mets tied the score in the bottom of the seventh when d'Arnaud drew a bases-loaded walk.

Harvey gave up two hits and one walk while striking out eight. Red Sox left-hander Henry Owens allowed two runs (one earned), five hits and four walks while striking out six in five innings.

NOTES: Dave Dombrowski, named Red Sox president of baseball operations on Aug. 19, spent 25 minutes before batting practice speaking to reporters in the visitor's dugout. He said RHP Clay Buchholz (right flexor strain), who has been out since July 11, won't pitch again this year. He also said LF Hanley Ramirez will continue to work out at first base with the expectation he'll play the position next year. Ramirez was a late scratch because of a fatigued right shoulder. ... This weekend marks the first time the Mets have hosted the Red Sox since 2001. Two teams -- the Cleveland Indians and Seattle Mariners -- have yet to play at Citi Field. ... Mets RHP Matt Harvey went 11 days between starts, his longest respite since he went 13 days between starts in July 2013.