Trailing 5-2 going to the bottom of the seventh, the Nationals were nine offensive outs from a sweep at the hands of the Mets.
They now lead 6-5 as we go to the ninth.
A Wilson Ramos RBI single in the seventh cut the Mets' lead to two, and then the Nats exploded for three runs in the eighth, with Jayson Werth's double to the gap in right-center scoring Ryan Zimmerman from first to cap the comeback.
Scott Hairston and Denard Span singled to start the eighth, and after a sac bunt front Bryce Harper (which had many in the press box in complete shock), Anthony Rendon pushed across a run with an RBI groundout.
Mets shortstop Omar Quintanilla then tried to make a miraculous spinning play on Zimmerman's grounder up the middle, but his throw to first was off the mark, and Span barreled all the way around from second to tie the game.
Werth then delivered yet again, and the Nats have the lead.
Rafael Soriano comes on to work the ninth, as the Nats try to salvage the finale of this three-game set.
Update: That'll do it. Soriano notched his 36th save with a perfect ninth and the Nats picked up a huge comeback win by a 6-5 score.
This victory gets them to within 6 1/2 games of the Reds in the wild card race, and avoids what would have been a devastating sweep.
Now comes a 10-game road trip, with three in Philadelphia up first.