Matt Festa had to wait a long time to pitch a home game for a New York team. A nearly three-hour rain delay and a few extra innings prolonged matters even more Sunday.

Staten Islanders hoped the axiom of it being “well worth the wait” rang true for the St. Joseph by-the-Sea HS product. Unfortunately, that wasn’t the case.

In his debut for the Mets, the 6-foot-1 right-hander entered a tie game in the 11th inning and surrendered five runs (four earned) to the Houston Astros in a 10-5 setback at soggy Citi Field.

Festa, who along with fellow pitcher Tyler Jay had been promoted from Triple-A Syracuse following Saturday’s loss in which the Mets’ bullpen blew an early lead, was in position to possibly get the win if he had blanked the Astros in the 11th.

Instead, the 31-year-old Festa gave up five runs on a walk and four hits — including a two-run single to Joey Loperfido and a two-RBI double to Trey Cabbage — as the Mets lost a series for the first time in a month. It left the Amazins with a 40-41 record at the exact halfway mark of the season entering a four-game set at Washington that begins Monday night.

After starter Luis Severino had spotted Houston a 4-0 advantage on a bunch of dinks and dunks, New York rallied to halve the deficit on a two-run double by Mark Vientos in the sixth inning and a two-run homer the following frame from Brandon Nimmo, his 100th career dinger.

Nimmo tied the contest 5-5 in the home 10th on a double with none out, but the Mets couldn’t plate him.

Tylor Megill and Danny Young were demoted to Syracuse to make room for Festa and Jay. The Mets will still be without closer Edwin Diaz for five more games following last Sunday’s 10-game suspension for having an illegal substance on his hands prior to throwing a pitch against the Cubs in Chicago.