It was only a matter of time before the Mets‘ bullpen fell back to earth. The new relievers excelled after the trade deadline, and while it hasn’t quite broken, it appears as though it’s starting to bend.

It sure did Sunday in the series finale against the Houston Astros at Citi Field. Left-hander Zac Thornton handed a one-run lead over to Jonathan Pintaro in the top of the sixth, only for the right-hander to give up a two-run homer. Left-hander Jefry Yan struggled with his command in the seventh, loading the bases with one out, and an error by first baseman Jared Young cost two runs.

The Mets lost 6-3, dropping their third straight series.

Thornton gave up a home run to the first batter of the game, Jeremy Peña, and the Mets came back in the bottom of the first to give him a lead with back-to-back homers off right-hander Ethan Pecko. For Francisco Lindor, it was his 14th of the season, and it was Juan Soto’s first since coming off the injured list with a left calf strain Saturday, and his 22nd on the year.

They manufactured another run in the fourth inning, when A.J. Ewing walked, stole second, and reached third base on a ball overthrown by the catcher. After Marcus Semien walked, Ewing scored on a double play by Luis Torrens.

Thornton battled the Astros. The rookie had some long at-bats and got into an early jam with two outs. That came in the second inning, when he allowed another run before retiring Yordan Alvarez, one of the leading candidates for AL MVP.

He left with a 3-2 lead after going five innings, giving up two earned runs on six hits and striking out five, using 97 pitches.

The Mets took three runs off Pecko (1-0), two earned, over five innings.

Pintaro (2-1) got the first two outs of the sixth inning before giving up a double to Yainer Diaz. LaMonte Wade Jr. pinch-hit a home run to put the Astros up 4-3, and AJ Blubaugh pitched around a one-out double in the bottom of the frame to keep the lead intact.

After getting the first out in the seventh, Yan loaded the bases by walking Isaac Paredes, giving up a single to Jose Altuve and hitting Jordan Walker with a pitch. He got Daulton Varsho to roll over on a sinker, sending a chopper to Young at first base, but Young’s throw home sailed well over Torrens’ head. Paredes was safe, and Altuve had plenty of time to come home from third.

Blubaugh, Bryan Abreu and Steven Okert blanked the Mets in the seventh and eighth, setting up left-handed closer Josh Hader for the save (21).