NEW YORK -- Coming off a historic 21-win August, the Mariners embarked on a three-city, 10-game road trip that could have major postseason implications given that two of their upcoming opponents -- the Reds and Rays -- are key players in the American League and the National League Wild Card races.

Their first stop, however, was Citi Field for a three-game series against the Mets, who sit well below the .500 mark. It was a prime opportunity for Seattle to keep its winning ways going into September, and possibly draw first position in the three-way battle for the AL West crown.

But the Mariners were unable to take care of business in Friday’s opener, suffering a 2-1 loss on a go-ahead eighth-inning RBI single from Mets designated hitter Daniel Vogelbach. Fortunately for Seattle (76-58), Houston (77-59) and Texas (75-59) also lost on Friday, allowing the Mariners to maintain the lead in their virtual tie with the Astros atop the AL West.

• Games remaining: at NYM (2), at CIN (3), at TB (4), vs. LAA (3), vs. LAD (3), at OAK (3), at TEX (3), vs. HOU (3), vs. TEX (4)
• Standings update: The Mariners (.567) hold a slight edge on the Astros (.566) for the AL West lead, by winning percentage. Seattle is currently the second-best division leader, meaning it would host a five-game AL Division Series vs. the winner of a Wild Card Series starting on Oct. 7.

Seattle’s red-hot offense -- which led the AL in slugging percentage (.493) and OPS (.864) and led the Majors in on-base percentage (.371) and wRC+ (143) in August -- was held in check by New York starter Kodai Senga. The 30-year-old rookie relied primarily on his trademark forkball, matching his career high with 12 strikeouts across seven innings.

Senga didn’t allow a hit until J.P. Crawford broke through in a big way to open the fourth, smashing a home run to center field.

“That forkball had way more movement than what I expected it to,” Crawford said. “I think it just dropped out the window. It was really impressive. He had everything working tonight and was able to get out of some tight situations. …

“Tip of the cap that he was able to throw that one, start at the letters and end up in the dirt. You don’t see a pitch like that too often.”

Mariners starter Logan Gilbert matched Senga stride for stride, only allowing a Brandon Nimmo solo homer in the sixth. Gilbert, who struck out nine in 6 2/3 innings, was lifted only when the Mets threatened in the seventh with two on and two outs. Manager Scott Servais turned to left-hander Gabe Speier, who got Nimmo to ground into a forceout at second base with his first and only pitch.

“Heck of a pitching performance on both sides tonight,” Servais said. “I thought Logan was really good, certainly on top of his game. Unfortunately, their guy was just as good. It’s the first time we’ve seen Senga. The split-finger, we knew coming into the game that’s his go-to pitch, and it was as advertised. Really good pitch. Obviously, it’s tough for our guys to lay off it.

“ … Any time you give up two runs, we expect to win the game, but they outpitched us. That’s just the way it went tonight.”

Beyond Crawford, only four Mariners managed one hit apiece off Senga -- Teoscar Hernández, Josh Rojas, Cal Raleigh and Julio Rodríguez, the latter of whom was making his return to the lineup after missing the club’s previous two games with left foot soreness.

The only Seattle player to notch a multihit game, Rodríguez tallied another knock off Phil Bickford in the eighth to record his 300th career hit. The reigning AL Rookie of the Year is the third-fastest Mariner to reach the milestone, behind only Ichiro Suzuki and Alex Rodriguez, and he boasts the longest active hitting streak in the Majors at 14 games.

Unable to string hits together as a group, the Mariners opened the door for the Mets to steal a game. With AL Reliever of the Month contender Andrés Muñoz on the mound, Vogelbach battled through a nine-pitch at-bat and then delivered the finishing blow, dropping Seattle to 21-23 in one-run games this season.

“We’re going to play a lot of close games, and you’re not going to win them all,” Servais said. “… To win close games, you got to make plays defensively and you got to get a big hit. They got it, and we didn’t.”