On the night that Pete Alonso returned to Citi Field, the Mets could have used a clutch RBI.

New York left nine men on base and went 0-for-3 with runners in scoring position in a 2-1 loss Monday to the Orioles (73-78) in front of a home crowd that showed a lot of love for the franchise’s home run king.

Alonso received warm ovations, a pre-game tribute video, and tipped his helmet to the fans before flying out to right in his first at-bat as a visitor in Queens. He finished 0-for-3 with a walk and a strikeout.

Gunnar Henderson hit a tie-breaking solo homer in the eighth inning off of Dedniel Núñez (1-1).

The Mets (69-81) had chances. Marcus Semien grounded out with runners at first and second to end the fifth.  Jared Young did the same in the third. Francisco Alvarez struck out with the bases loaded to end the second.

In his second start since returning to the majors, Jonah Tong allowed one unearned run on four hits over a career-high-tying six innings. He struck out six and walked one. One year and two days ago, Tong started when Jacob deGrom returned to Citi Field as a Ranger. In that start, Tong gave up six earned runs and didn’t escape the first inning.

Jonathan Pintaro threw a scoreless seventh. Kodai Senga allowed two hits, but struck out the side in a scoreless ninth.

A.J. Ewing tied the game at 1-1 with a solo homer (10) in the fourth. He became the 11th Met with 10 or more homers this season, a team record.

Heston Kjerstad drove in a run in the second when his hard ground ball took a bad hop and eluded first baseman Brett Baty for a two-out double. Jackson Holliday, who had advanced to second on Alvarez’s major league-leading 10th passed ball, scored.

Brandon Young allowed one run on five hits over five innings. He struck out six and walked five.

“New York is always going to feel like some sort of homecoming because for me the city is really special,” Alonso said before the game.

“Two things can be true at the same time,” he said. “I’m very happy and appreciative of my time I spent as a Met, and I’m beyond grateful and appreciative for the Baltimore Orioles.”

Stat of the Game

Alonso and Francisco Lindor both stayed stuck on 299 career homers. The only time two players hit No. 300 in the same game was when Jermaine Dye and Paul Konerko did it back-to-back for the 2009 White Sox.

Player of the Game

Tong has struck out 13 and walked two in two September starts. In three MLB appearances earlier this season before he was sent to the minors, he struck out seven and walked seven.

On Deck

MLB will celebrate Roberto Clemente Day. Every player will wear a No. 21 patch on his jersey. Sean Manaea (5-7, 4.79 ERA) will try to break a string of five consecutive starts where he has allowed four earned runs or more. RHP Shane Baz (6-15, 4.05 ERA), who is tied with Cleveland’s Tanner Bibee for the MLB lead in losses, goes for Baltimore. The game is at 7:10 p.m. ET on SNY.