In addition to the abuse of Moreta, the Reds were two outs away from a 3-2 victory in the ninth when Hunter Strickland gave up a game-tying double to Starling Marte.
The bullpen blow-up came one night after the bullpen pitched 4 1/3 scoreless innings in a 1-0 win.
And the walk-off concept. After going 77 games without one, the Reds had performed it twice in their previous three games, including the 1-0 win.
They had the opportunity Wednesday after the Mets tied it in the top of the ninth. But New York relief pitcher Adam Ottavino went 1-2-3, striking out Albert Almora Jr. and pinch-hitter Tyler Naquin for the final two outs.
Then came the 10th … and disaster for the Reds.
Pinch-runner Ender Enciarte was the ghost runner. With one out, Dominic Smith doubled into the right-field corner for a run.
With two outs, manager David Bell chose to intentionally walk Luis Guillermo. And it blew up in his face like a leftover Fourth of July firecracker. Pinch-hitter James McCann singled on Moreta’s 0-and-2 pitch to make it 5-3.
And Brandon Nimmo furnished the coup d’etat with a three-run home run.
The Reds, who were outhit, 16-5, were helpless in the bottom of the 10th against Edwin Diaz. He struck out the side — Mike Moustakas, Brandon Drury and Tommy Pham.
Reds starter Graham Ashcraft had to feel as if he spent 2 1/2 hours in a sauna, doing push-ups.
On a hot, muggy night, he had to work, work, work. The Mets put their leadoff hitters on base in each of the first four innings. They sprayed 10 hits all over the GABP outfield grass against him.
Yet when Ashcraft left after six innings, he had given up only two runs and the Reds led, 3-2. The Mets were 1 for 7 with runners in scoring position and stranded five.
The Mets, who didn’t score in nine innings Tuesday during a 1-0 loss, scored a first-rinning against Ashcraft.
Nimmo led off the game by getting hit by a pitch, the 57th time a Mets batter was hit by a pitch. And the Reds lead the league in hitting batters with 51.
With two outs, Pete Alonso singled, the first of his four hits, and Jeff McNeil singled to make it 1-0.
Molten-hot Nick Senzel provided the Reds with a 2-1 lead in the second inning against Mets starter David Peterson, who took the mound with a 5-and-1 record. He walked Matt Reynolds with one out, one of five walks he issued in 3 2/3 innings. Senzel turned on the first pitch and drilled his third home run.
The Reds expanded the lead to 3-1 in the third on former Met Drury’s single, a stolen base, a wild pitch, and a ground-rule double by Matt Reynolds.
Peterson walked the first two Reds in the fourth, but Senzel was picked off second base by catcher Tomas Nido when Michael Papierski missed a bunt attempt.
New York crept to within 3-2 in the fourth on a double by Smith and Nimmo’s two-out single.
Joel Kuhnel replaced Ashcraft in the seventh and retired the first two Mets. When Alonso singled, Reiver Sanmartin arrived to end the inning on one pitch, a ground ball by McNeil.
Sanmartin pitched a 1-2-3 eighth, the first time the Reds retired the Mets in order all night.
That left it up to recent closer Strickland to twist the lid tight in the ninth. Instead, he opened the jar and permitted the Mets to tie it, 3-3.
With one out, Nimmo singled and scored on Marte’s double to left. Francisco Lindor grounded to the mound, sending the potential go-ahead runner to third.
The Reds tempted disaster by pitching to Alonso, the National League’s RBI leader with 69. He fouled out on the first pitch to catcher Papierski.
Then came the fateful 10th.
Before the game, pitcher Tyler Mahle was placed on the injured list with back issues. He was scheduled to pitch the first game of a doubleheader Thursday against the Pittsburgh Pirates. Instead, he is not expected back until after the All-Star break.
In addition, Jonathan India was hit by a pitch leading off the first inning and left the game with a sore left ankle.