For the Mets, it’s on to Super Tuesday with a smile.

In a season of mistakes, the Mets hit their lowest point yesterday when they threw the ball away in the infield three times on one fifth-inning play, their version of the Buttfumble leading to two Cubs runs.

Kirk Nieuwenhuis’ three-run walkoff home run changed everything, though, lifting the Mets to a 4-3 victory over Carlos Marmol and the lowly Cubs at Citi Field and setting the stage for Atlanta.

One of the Mets’ younger players finally contributed to a win, and now they enter Phase II of their season, putting everything on the powerful right arms of Matt Harvey and Zack Wheeler, who will make his major league debut tomorrow in the second game of a doubleheader at Turner Field against the Braves.

It’s Wheels Up.

Marlon Byrd, who started the ninth-inning rally with a leadoff home run off Marmol to get the run-starved Mets on the board, spoke for his teammates when he talked about the anticipation of seeing Wheeler pitch.

“I can’t wait to see Wheeler,’’ Byrd told The Post. “Having Harvey and Wheeler back-to-back now, I’m excited.

“I remember coming into spring training, and I had just finished playing in the Caribbean Series the week before, so I was ready. I was swinging the bat well off our pitchers, and then I saw Wheeler’s first pitch and he was the only guy I wouldn’t swing off of, I didn’t want him messing me up. I said, ‘I’m not swinging, he might break my bat or something.’ He’s got electric stuff and God, everybody is excited to see what he can do.’’

The Mets have to get through Tim Hudson tonight and then get their look at the flame-throwing future.