PITTSBURGH — A rough weekend against an underwhelming opponent was on the brink of worsening for the Mets as Sunday’s ninth inning dawned.

But one of the quietest bats in the lineup had ammunition remaining in it, allowing manager Luis Rojas’ crew to save face before leaving town — long after Rojas had been ejected from the game. Michael Conforto cleared the center-field fence with a two-run homer, capping a methodical comeback and 7-6 victory over the Pirates at PNC Park.

The Mets, who lost two of three in the series and went 3-4 against the Pirates in seven games that wrapped around the All-Star break, rallied from a six-run deficit in the first inning on the strength of a strong bullpen performance and gritty offensive attack.

In a weekend the Mets placed Jacob deGrom and Francisco Lindor on the injured list and suffered through a walk-off grand slam against Edwin Diaz, they could at least exhale a little before heading to the next stop, Cincinnati.

“We’re going to continue to expect to win, we’re going to continue to show up and play to win, regardless of the guys that we don’t have,” Conforto said. “That is the culture that we have built … we’ll keep the ship steady until those guys are back.”

Conforto’s blast against Richard Rodriguez was only his fourth of the season. He had been hitless in his first three at-bats, including a strikeout to end the sixth with the tying run at second base.

Taijuan Walker recorded only one out in the game and was removed after the Pirates had taken a 6-0 lead. With the bases loaded and the Pirates already up 3-0, Kevin Newman’s squib along the third-base line was swatted toward the dugout by Walker, who believed the ball was foul. Plate umpire Jeremy Riggs ruled the ball fair, and all three Pirates on base kept running and scored as Walker argued.

An irate Rojas was immediately ejected and had to be restrained from going after Riggs. It was by far the most emotion Rojas has shown in his two seasons managing the team.

“He was fired up for sure, and I think that got the whole team fired up — to see him have our backs out there,” Walker said. “He’s usually cool-mannered and everyone thought it was foul and it was a big moment early in the game, but I think he got everyone fired up in the dugout and we really wanted to win that game.”

Afterward, Walker and Rojas both maintained their belief the ball was foul. Rojas said his anger stemmed from the fact the play couldn’t be reviewed. Rojas had at least hoped Riggs would convene with third-base umpire Marvin Hudson to discuss the call.

Rojas said his show of emotion wasn’t intended to fire up the team, even if that might have been a by-product.

“My intention was just to get the call right,” Rojas said. “The replay has kind of diminished the managers arguing on the field, but since that play is not reviewable, I’m coming out but my purpose there is just to get the call reversed.”

Walker’s nightmare inning started with Bryan Reynolds’ RBI single after Wilmer Difo stroked a one-out double. Ben Gamel walked and John Nogowski’s two-run double put the Mets in a 3-0 hole. Newman’s dribbler along the third-base line followed.

Travis Blankenhorn’s first major league homer, a three-run blast in the fourth, got the Mets back in the game, slicing their deficit to 6-4. Jonathan Villar and Tomas Nido each singled to begin the rally before Blankenhorn crushed a 91 mph fastball from JT Brubaker over the fence in right-center.

Dominic Smith’s double in the sixth allowed Jeff McNeil to score another run, on Gregory Polanco’s throwing error, that pulled the Mets within 6-5.

The Mets began their comeback in the third on Smith’s two-out RBI single. Brandon Nimmo walked to begin the rally before McNeil singled.

Drew Smith gave the Mets 2 ²/₃ innings of shutout relief behind Walker. Aaron Loup loaded the bases in the sixth with nobody out, but struck out the next three batters to keep the Mets’ deficit at 6-5. The lefty Loup pitched two scoreless innings in lowering his ERA to 1.48. Jeurys Familia and Travis May got the Mets to the finish line.

“It’s a huge game for us,” Rojas said. “I’m happy for the bullpen and I’m happy for [Conforto], who delivered that big hit for us.”