The Union are 7-10-2; New England is 6-10-5. Both teams have 23 points. This type of win, over a team that had been ahead of them in the standings, is what the Union need to earn one of the five Eastern Conference playoff berths.
The two teams are tied for eighth, nine points behind fifth-place Chicago, which has played two more games than the Union.
"It's a confidence-builder, and shows the character of our team," McInerney said. "We want to be in the playoffs and don't give up until the end of the game."
The winning shot came on a picture-perfect play, with midfielder Brian Carroll feeding defender Sheanon Williams down the right flank. Williams sent a perfect cross to the far post, and McInerney headed down on the ball for his fourth goal of the season.
"Sheanon played a good ball to the back post, and I got open and headed it down," McInerney said.
McInerney then did a spontaneous PPL Park leap into the arms of fans. Not everybody in the sellout crowd of 18,598 greeted him; it just seemed that way.
New England had taken a 1-0 lead in the 12th minute on a spectacular long-range goal by Saer Sene, whose shot from 30 yards out dipped and had keeper Zac MacMath going the wrong way. The ball drifted in to the left of MacMath inside the near post.
"I took a step where I thought it was going, and it dipped back in, and I tried to get a hand on it but didn't have enough on it to get it out of the goal," MacMath said.
After being outscored and outplayed in the first half, the Union changed course.
"I thought we got away from our game in the first half, and we were dumping far too many balls, playing far too direct," Union interim team manager John Hackworth said.
Forward Antoine Hoppenot earned his first start for the Union, and he provided plenty of energy.
In the second half, the Union started out lethargic but got the equalizer on a penalty kick by Freddy Adu in the 59th minute. Revs defender Kevin Alston, playing in his 100th MLS game, tripped McInerney just inside the box. The play was set up by Gabe Farfan, who sent a through ball in on goal to McInerney.
After the goal, the Union continued to apply the pressure.
The Union chipped away until McInerney's game-winner, earning their fourth consecutive MLS win at PPL Park.
Contact Marc Narducci at 856-779-3225 or firstname.lastname@example.org, or follow @sjnard on Twitter.