Mets starting pitcher Noah Syndergaard flips his glove as he...

Mets starting pitcher Noah Syndergaard flips his glove as he walks off the field after being removed during the eighth inning against the St. Louis Cardinals, Thursday, April 26, 2018, in St. Louis. Credit: AP / Jeff Roberson

ST. LOUIS — Mickey Callaway’s demeanor, calm with the occasional slight smile, was the same as it was after all those consecutive wins this month.

Sure, the Mets lost this one, 4-3, in 13 innings to the Cardinals on Thursday. And yes, they’ve lost seven of their past 11 games, and this one came after Jeurys Familia’s third blown save in his last five appearances and wasted Noah Syndergaard’s best start this season.

But Callaway is all about perspective, not rushing to judgment.

“It would be frustrating if we weren’t where we’re at in the standings,” he said. “We’re still in a pretty good spot [first place in the NL East]. What has happened in the last week or week and a half is not going to continue to happen. That’s just not going to happen.

“To be where we’re at — and things probably haven’t gone our way numerically as far as stats — I’m pretty pleased with it.”

The Mets (15-8) led by a run in the eighth and the 10th, but Robert Gsellman and Familia each allowed the Cardinals to tie it. The run against Familia scored when Jose Martinez lined a two-out double over Juan Lagares’ head and off the centerfield wall. Lagares said he lost the ball in the sun a bit.

“I still had no chance,” he said. “I did my best to try, but he crushed it.”

Dexter Fowler won it for St. Louis with a walk-off single off righthander Paul Sewald. It was the first hit by a lefthanded hitter against Sewald in 16 plate appearances this season.

“That’s a tough one to lose, especially when you have a lead [late] and the way Noah pitched,” Sewald said.

Carlos Martinez stifled the Mets for six innings. The Mets scored a run before making an out — Yoenis Cespedes doubled down the leftfield line to drive in Brandon Nimmo (hit by a pitch) — but Martinez settled in, striking out three and walking none.

Cespedes’ double was the Mets’ only extra-base hit. They had chances but stranded 11 men and went 0-for-7 with runners in scoring position.

Syndergaard allowed two runs (one earned) in 7 1⁄3 innings, his longest start since August 2016, and had nine swings-and-misses on his changeup, the second-highest total of his career.

“Today felt a lot better in terms of my delivery. I wasn’t fighting my body to deliver a pitch,” he said.

For weeks, adequacy frustrated Syndergaard. His outings were too short. His pitch counts were too high. His stuff was fine — “pretty dominating,” he said last week — but the results didn’t match. Finally, on Thursday, the results matched.

Syndergaard gave up six hits and struck out seven. He didn’t walk anybody. He had a chance at a complete game if his fielders had come through.

“It wasn’t really about bad defense,” Callaway said. “It was just out of reach just by a hair.”

St. Louis didn’t have a baserunner until the fourth, when Tommy Pham singled with one out. The Cardinals didn’t have anybody reach second until the seventh, when Pham doubled.

That’s when it started to fall apart for Syndergaard, with a hearty assist from the defense. Pham’s was the first of two doubles that bounced off the glove of a fielder. Cespedes, charging hard toward the leftfield foul line, slid but didn’t make the catch. Paul DeJong later doubled off the glove of third baseman Todd Frazier.

In the eighth, Greg Garcia reached on Amed Rosario’s error. After Gsellman relieved Syndergaard, Garcia scored on a single by Pham.

“We’re still very confident in this clubhouse,” Syndergaard said. “We’re not in panic mode by any means.”