NEW YORK -- The confidence of New York Mets right-hander Noah Syndergaard doesn't present itself with snarling gyrations or a laid-back smoothness, a la fellow right-handers Matt Harvey and Jacob deGrom.

But everyone at Citi Field on Friday night saw a quietly self-assured pitcher who is beginning to figure out how good he can be.

Syndergaard struck out a career-high 13 in eight dominant innings and the Mets provided him all the support he needed with four first-inning runs in a 4-2 win over the Arizona Diamondbacks.

Syndergaard (4-4) allowed one run, four hits and two walks. He has given up one run or less in four of his last five starts, a stretch in which he has a 1.97 ERA and has struck out 38 batters in 32 innings.

"He's pitching good right now and he knows it," Mets manager Terry Collins said. "He went out again tonight and gave us a tremendous outing."

The evening didn't start in promising fashion for Syndergaard. His second pitch was laced for a double by Diamondbacks center fielder A.J. Pollock, who stole third and scored on a sacrifice fly by first baseman Paul Goldschmidt.

But Syndergaard allowed just one runner to get beyond first base the rest of the way. He struck out at least one batter in every inning, struck out every member of the Arizona starting lineup at least once and recorded nine of his final 13 outs via the strikeout.

"He knows his stuff can play here -- and not only play here, but really dominate," Mets catcher Kevin Plawecki said. "He's been doing tremendous. More of these good starts he puts together, the confidence just keeps building. So that's really good for him."

Syndergaard's stuff was as impressive as his body language was understated. In the sixth inning, he shrugged when he miscommunicated with Plawecki yet still struck out third baseman Jake Lamb to complete an inning in which he whiffed the side on just 13 pitches. Plawecki wanted a high fastball and Syndergaard ended up throwing it down the middle of the plate.

Syndergaard was still mixing his curveball and changeup with a 97 mph fastball in the eighth inning, which he ended by retiring Goldschmidt on a popup to Plawecki on his 116th and final pitch. He quietly pumped a fist as he walked off the mound and into a sea of high-fiving teammates in the dugout.

"Really good -- really good," Diamondbacks manager Chip Hale said of Syndergaard. "I kind of expected him to be more of a power pitcher -- you know, just throw and let it fly -- but he was really pitching."

The towering Texan -- Syndergaard is listed at 6 feet 6 and 242 pounds -- remained low-key after the game, when he barely spoke above a whisper in front of his locker.

"It was awesome, it was a lot of fun," Syndergaard said. "The ability to change speeds and keep them off-balance was the reason for my success tonight."

Syndergaard was also helped by a rare early outburst by the Mets, who have scored four runs or fewer in 21 of their last 23 games.

With two outs in the first, slumping first baseman Lucas Duda -- who entered the game with just nine hits in his last 73 at-bats and no homers since June 18 -- hit a mammoth three-run homer to center. Left fielder Michael Cuddyer, who hadn't homered since June 5, followed with a blast just beyond the reach of left fielder David Peralta.

"Tonight the two guys that we hope to ride in the second half broke out a little bit," Collins said. "If we get 'Cuddy' and Lucas going, it just changes the whole dynamic of the lineup."

Right-hander Jeurys Familia picked up his 25th save despite allowing a run in the ninth, when Diamondbacks right fielder Yasmany Tomas hit a leadoff triple and scored on a one-out single by catcher Welington Castillo.

Cuddyer and second baseman Wilmer Flores each had two hits for the Mets (45-42), who won for the fifth time in seven games and ensured they would hit the All-Star break with a winning record.

Tomas had two hits for the Diamondbacks (42-43), who were trying to move above .500 for the first time since April 22.

Diamondbacks starter Chase Anderson (4-3) allowed four runs, eight hits and two walks while striking out four in 4 1/3 innings. He survived an injury scare in the fourth, when he was hit by a line drive off the bat of Mets center fielder Juan Lagares.

"He battled and was able to limit it to the four, which in most games would give us a chance to win," Hale said. "We just ran into an extremely impressive pitcher in Syndergaard."

NOTES: The Mets placed rookie LHP Steven Matz on the 15-day disabled list, retroactive to July 6, with a torn left lat muscle and recalled INF Danny Muno from Triple-A Las Vegas. Matz, who has won both of his big league starts and collected five RBIs in six at-bats, will be shut down for three weeks before being re-examined. ... Mets LF Michael Cuddyer (left knee) returned to the lineup after sitting out Tuesday and Wednesday. ... Diamondbacks CF Ender Inciarte (right hamstring strain) was expected to play in his second rehab game for Double-A Mobile on Friday night. ... Diamondbacks manager Chip Hale said he expected RHP Jeremy Hellickson, who left Wednesday's start with a blister on his right thumb, to return to the rotation after the All-Star break.