Atlanta United had the lead and the sellout home crowd in its first match as an expansion team.
The New York Red Bulls had the experience that made the difference in a second-half turnaround that included some unexpected help from Atlanta — a decisive own goal.
New York scored two second-half goals in a span of about 6 minutes and the Red Bulls rallied for a 2-1 victory over Atlanta on Sunday night.
"Imperfect is what I would call that performance, but it's early in the year so we are still working through getting our group sharp and getting the tactics down," Red Bulls coach Jesse Marsch said. "Atlanta tested us in big way in the first half and we took a punch but hung in there."
New York's comeback spoiled the inaugural Major League Soccer match for Atlanta, which had the support of a sellout crowd of 55,297.
"We want to win our games at home, but New York is an experienced team," Atlanta goalkeeper Alec Kann said. "We would have liked to have finished them off in the second half, but we didn't."
Officials ruled Atlanta's Anton Walkes kicked the ball into the United net for the Red Bulls' go-ahead goal. New York's Bradley Wright-Phillips appeared to score the goal on a pass from Kemar Lawrence in the 83rd minute. The decisive contact on the ball was ruled to have come from Walkes, who was defending Wright-Phillips.
Yamil Asad scored the first goal in United history late in the first half for a 1-0 lead.
The Red Bulls finally pulled even in the second half. Shortly after Atlanta goalkeeper Alec Kann blocked a shot by New York's Felipe, the Red Bulls scored on a header by Daniel Royer in the 76th minute.
It was a crushing loss for United.
"I didn't like the second half," Asad, who is from Argentina, said through an interpreter. "We have a lot of things to work on. We gave them too many opportunities."
Atlanta United's Carlos Carmona was sent off after drawing a red card in the 88th minute.
Positioned to the left of the goal, Asad waved his arm to show he was open and Tyrone Mears delivered a well-placed pass. Asad quickly hooked the shot past goalkeeper Luis Robles in the 25th minute for the first goal in United history.
Asad fell to the grass near the end line. Several teammates piled on top of him in a celebration cheered by fans.
Robles dove and blocked a shot by Josef Martinez in the 43rd minute, leaving Atlanta United with the 1-0 lead.
The Red Bulls had the Eastern Conference's best record last season despite a 1-6 start but lost to Montreal in the playoffs. New York lost 2-0 at Vancouver in a CONCACAF Champions League quarterfinal Thursday, leaving a long flight and little recovery time before the MLS opener.
United owner Arthur Blank, also owner of the NFL Atlanta Falcons, said before the match "Atlanta has responded as beautifully as you can imagine."
United has sold more than 30,000 season tickets, a record for a MLS expansion team.
Blank called the sellout "a tribute to Atlanta" and said "to see the enthusiasm of our fans and their passion for our team just makes my heart feel good."
United and the Falcons will share the new $1.5 billion Mercedes Benz Stadium, being built beside the Georgia Dome. United's first match at the new stadium is scheduled for July 30 against Orlando City.
Until then, Georgia Tech's Bobby Dodd Stadium is United's temporary home. A lack of width was the major challenge in the football facility, with only 2 yards between the pitch and the brick wall of the stands on one side.
MLS Commissioner Don Garber attended the match and said Georgia Tech's stadium "is perfect for now." Garber said "we can't wait to get into Mercedes Benz Stadium."