WASHINGTON — A lazy afternoon at the ballpark with a comfortable lead turned into a rare bullpen meltdown for the Mets on Sunday.
In the seventh, most of a six-run lead against the Nationals got flushed — largely through a combination of a ball Juan Soto lost in the sun and ineffective relief from José Buttó.
In the ninth, Ryne Stanek blew his second straight save opportunity by surrendering a game-tying RBI single to CJ Abrams before Pete Alonso’s throwing error gave the Mets an 8-7 walk-off loss at Nationals Park.
Alonso fielded Luis García Jr.’s grounder and threw over Stanek’s head as the pitcher covered first, allowing the winning run to score.
It was the Mets’ second walk-off loss to the Nationals in three days.
Tylor Megill dominated through six innings, allowing only one hit, but after he returned to the mound for the seventh, he got burned by a ball Soto lost in the sun for a García leadoff double.
It opened the door to the Nationals scoring five runs in the inning, two of which were charged to Megill.
The Nationals’ big hit — a three-run homer by Riley Adams that sliced the Mets’ lead to 7-6 — was surrendered by Buttó.
Over 6 ¹/₃ innings, Megill allowed three earned runs on three hits with nine strikeouts and one walk.
Megill allowed a two-out solo homer to Dylan Crews in the second.
It snapped a 14-game streak in which Mets starting pitchers hadn’t allowed a homer, dating to April 11 when Griffin Canning surrendered a blast to A’s outfielder Miguel Andujar.
The Mets jumped on Mitchell Parker for five runs in the first inning, sending 10 batters to the plate, with four walks helping to fuel the outburst.
Mark Vientos’ sacrifice fly brought in the game’s first run after Francisco Lindor had singled leading off and Soto and Alonso each walked.
Starling Marte walked and Brandon Nimmo’s sacrifice fly gave the Mets a 2-0 lead.
Luis Torrens delivered an RBI single and a second run scored on the play on Crews’ throwing error.
Luisangel Acuña’s RBI single extended the lead to 5-0.
Soto doubled leading off the second and Marte’s RBI fielder’s choice widened the lead to 6-0.
Torrens’ second hit of the game, an RBI double in the fifth, placed the Nationals in a 7-1 hole.
But the Mets barely got through the seventh with the lead.
After Soto lost Garcia’s ball in the sun for a leadoff double, Josh Bell delivered a one-out RBI single.
Buttó entered and allowed a single to José Tena before Alex Call’s RBI single brought the Nationals within 7-3.
Butto fell behind 3-1 in the count to Adams, who launched a three-run homer to right-center against Buttó.
Buttó escaped with a 7-6 lead by retiring Abrams to end the inning.