Seth Lugo, after hitting his first career home run, gets...

Seth Lugo, after hitting his first career home run, gets the silent treatment from teammates in the dugout, but goes ahead and high-fives imaginary teammates, during the Mets' 9-3 victory over Colorado on Saturday, July 15, 2017, at Citi Field. Credit: Getty Images / Adam Hunger

The towering fly ball smacked against the porch in left-center, a loud sign of defiance. Wasn’t it just Friday that general manager Sandy Alderson had all but put a “For Sale” sign on the Mets’ clubhouse? Unless, of course, the Mets played “exceedingly well” down the stretch.

About that: Let’s get one thing straight. No one is saying the Mets shouldn’t be sellers at the trade deadline and, indeed, things looked dicey at times in the later innings of their 9-3 win over the Rockies last night. And it’s certainly hard to imagine a world where the Mets can keep this up for an extended time. The first half was painful and their propensity for injury reared itself again in the sixth inning, when Yoenis Cespedes was pulled after making an awkward slide in the outfield.

But there has been an air of rebelliousness to these last two games, which come as the team is putting the final stitches in its white flag. The Mets have gotten solid starting pitching from Jacob deGrom and Seth Lugo and they’ve scored 23 runs in that span. And that towering fly ball? Why, that improbability was courtesy of Lugo himself. His solo shot in the third was his first homer since college.

When he returned to the dugout beaming, his teammates gave him the silent treatment and Lugo — mischievously defiant himself — high-fived the air. He took his congratulations from imaginary teammates and even threw up his helmet and caught it himself. The dugout eventually cracked, showering him with his due celebration.

“When I was running around the bases, it was pretty surreal,” he said. “I always looked forward to that moment . . . It just came naturally. Everyone who hits a home run, [Asdrubal Cabrera] takes off their helmet, and I always looked forward to that. I knew I was going to get a home run sometime, but I had to give [the celebration] to myself.”

His homer, off reliever Chris Rusin, gave the Mets an 8-0 lead and left everyone wondering where this version of the team has been.

The Mets drew to within 8 1⁄2 games of the Rockies in the race for the second wild-card spot.

After his last painful start against the Nationals, Lugo bounced back nicely: He didn’t allow a runner to reach scoring position until the fifth inning, and though he allowed two runs in the sixth and another in the seventh, he left the game with a five-run advantage. He allowed seven hits with two walks and five strikeouts.

“He pitched very well,” Terry Collins said. “He changed speeds, again, like we know he can do . . . When we get well-pitched games, we know that can be the difference.”

The only bad news for the Mets came in the top of the sixth, when Cespedes took a tumble while trying to run down Nolan Arenado’s double. The Mets don’t believe the injury is serious and, other than that blip, everything came up Mets.

They scored four runs in the first. Tyler Chatwood walked Michael Conforto and Cabrera and, after Chatwood coaxed a shallow flyout from Cespedes, Jay Bruce pounced for his 24th homer, more than 420 feet to center, for a 3-0 lead.

Chatwood then walked T.J. Rivera and was pulled with an undisclosed injury. Rusin replaced him and three batters later, Travis d’Arnaud drove in the fourth run of the inning with a single to center.

In the second, Cespedes singled with two outs, advanced to third on DJ LeMa hieu’s error at second base and scored on Rivera’s single. Lucas Duda followed with a two-run double down the rightfield line.

The bullpen strung together 2 1⁄3 innings of scoreless relief and Jose Reyes added his ninth homer of the season.

“It’s very important, very important,” Bruce said of this tiny, hopeful stretch. “It’s just two games. There’s a lot of baseball to play. We still have to play great, but we just want to give ourselves a chance.”

Last night, they played pretty close to great. Some might even say exceedingly well.