CINCINNATI — This is how it ends. Not with a thunderbolt but with a whimper.

The Mets went 0-for-6 with runners in scoring position, struck out 12 times, had a terrible miscue in the field by Todd Frazier in the first inning and managed only three hits.

The run that beat them came on a two-out Christian Colon single up the middle in the eighth off a 3-2 Seth Lugo curve ball, a simple slap up the middle by a player who was just called up Monday.

The Reds came away with the 3-2 victory Saturday at Great American Ball Park when closer Raisel Iglesias cut through the final three Mets hitters, striking out Robinson Cano swinging, Wilson Ramos on a called strike three then ending the day by catching Michael Conforto looking at another strike three to end the game.

The 2019 season essentially came to an end as well for the Mets as they fell four games behind the Brewers in the loss column with eight to play. This would take the Miracle of Miracles.

The Mets have been climbing out of the abyss. The climb is too steep, with no room for error. The only sound that could be heard in the clubhouse for the longest time was the sound of brushes, wielded by clubhouse attendants, removing dirt from the players’ cleats.

Players left quickly.

The severity of the loss was in the air. The Brewers would have to have a historic collapse and the collapsing Cubs would have to continue to falter while these flawed Mets would have to run the table.

In the end, in all baseball seasons, the toll must be paid. All the dreadful losses from earlier in the season have to be figured into this 80-74 mix.

“Today hurts,’’ said Zack Wheeler, who pitched seven strong innings, allowing two runs, one earned while walking one and striking out seven.

The Reds presented the Mets with plenty of chances to make up for a two-run first inning, in which Frazier committed an error then did not play through on a Aristides Aquino ground ball to third with the bases loaded that took him into foul territory. Frazier hesitated on his throw to first base as Aquino was safe and a run scored.

Frazier, as is his standup style, owned up to his mistake, but it was too late for this day, too late for this season, barring a miracle. There is never just one reason why a game is lost. There are 27 outs to get it right, but sometimes one big mistake can’t be fixed.

Sometimes a team can’t overtake the hole they’ve dug for themselves throughout the season.

“It’s a tough one, these are games we are supposed to win, Wheeler pitched a hell of a game,’’ Frazier said. “We had opportunities and just didn’t get it done.’’

As for the dagger of the Aquino ground ball, Frazier made a fatal flaw, fielding the ball behind the bag across the line, assuming the ball was foul. Third base umpire Mark Ripperger called it fair.

“You are not supposed to assume in baseball I made a bonehead mistake,’’ Frazier said. “I actually thought it was foul. I remember doing it one time when I was younger and I told myself always play through. I just hesitated for a second and I probably could have had the guy at home. Cost us one, maybe two runs. It’s the old story, you don’t think, you have to assume that is a fair ball and play it out.’’

Baseball is cruel, but it is fair when the umpire says its fair.

“He looked back at the umpire instead of just playing it out,’’ manager Mickey Callaway said of the Frazier mistake.

The eventual winning run got on base via an eighth-inning walk by lefty Justin Wilson.

“It hurts, we had multiple chances,’’ Callaway said. “The way we lost hurts, a couple of mistakes in the field and we had plenty of chances at the plate. We just didn’t come through. I think we struck out on almost every chance we had with runners in scoring position. We needed a sac fly here, just touch the ball there and we just didn’t get it done.’’

Sounds much like the Mets’ 2019 season.