Ismael Tajouri-Shradi scored the game-winner in the 90th minute as 10-man New York City FC rallied to beat Los Angeles FC in Major League Soccer on Saturday.
Alfredo Morales flicked on a corner by Jesus Medina and Libyan forward Tajouri-Shradi, unmarked at the back, fired home the winner with his left foot.
Four minutes earlier, NYCFC had been reduced to 10 men when Uruguayan midfielder Nicolas Acevedo was sent off after a reckless tackle on Latif Blessing.
"It's a game that we should not lose," said LAFC coach Bob Bradley, whose team went up 1-0 in the 56th minute, when Corey Baird slotting home form the near post.
NYCFC equalized in the 70th through Medina, who curled in a left-footed shot that eluded goalkeeper Pablo Sisniega.
It was LAFC's error that made Medina's goal possible, as NYCFCs Anton Tinnerholm seized upon an errant pass from the Angelenos and found the Paraguayan striker.
NYCFC coach Ronny Deila called it "by far the biggest win" of his tenure in New York.
"Last year when we played Toronto away, Columbus away, I think we haven't been close to winning.
"We had Orlando last year, we improved. We made it an even game and this year now we beat Philadelphia away and Orlando draw (away).
"Now win here in LA, that's saying something about the group and that we're coming far now to work together as a group."
It was a deflating defeat for LAFC, who had Mexico international Carlos Vela in action for a full 90 minutes for the first time this season as he returns from a quadriceps injury.
Among other matches Saturday, a brace from Ola Kamara fueled DC United to a 3-0 victory over Inter Miami in the Florida club's first match since they were hit by a record $2 million fine for violating roster and salary rules in the signing of French World Cup-winner Blaise Matuidi.
Paul Arriola also scored for DC, who spoiled Inter's first home match with a full-capacity crowd at DRV PNK Stadium.