The goalkeeper stoned Dwayne De Rosario to ensure his side would move back into a tie atop the Eastern Conference.
Goals from Lloyd Sam and Tim Cahill, along with a penalty kick save from Luis Robles, led the way for New York, which played the final 18 minutes with 10 men following an Ibrahim Sekagya red card. Nick DeLeon scored for the visitors.
Red Bulls coach Mike Petke rolled the dice tactically, sitting star striker Thierry Henry until the 58th minute after the two were involved in a midweek training scuffle.
It took only eight minutes for New York's adjusted lineup to strike. Collecting the ball on the right side of the box after Cahill was taken out by Dejan Jakovic, Sam hit a chip that rang the far post, bounced off United goalkeeper Bill Hamid and crossed the goal line.
United drew even in the 36th minute. Collecting a long ball into the box from Dwayne De Rosario, DeLeon took a touch toward goal to evade left back David Carney before hammering a point-blank shot past Robles for his first goal of 2013.
But New York regained the lead two minutes later. Turning around Jakovic on the left flank, Jonny Steele got off a cross to the far post. Rising above Daniel Woolard, Cahill nodded home a shot for his eighth tally of the season.
In the 72nd minute, the tide appeared to turn in United's favor. Shielding the ball in hopes Robles would collect, Sekagya badly misplayed the sequence and ended up hauling De Rosario to the turf — earning himself a red card and giving United a penalty kick.
When De Rosario stepped up to the spot, however, Robles turned aside the low blast with ease.
The Red Bulls (12-9-6) moved into a tie with Montreal for the top spot in the Eastern Conference. New York also retook the Atlantic Cup thanks to its 2-0-1 mark in the season series with United (3-18-5).