Atlanta, Nov. 26 -- After the final whistle blew, the Atlanta players lingered in the middle of the pitch, doling out hugs and soaking up the cheers of more than 70,000 fans.

Everyone knew this was a huge step toward the MLS Cup.

Everyone knew how much this meant to a city that has known so much sporting heartbreak.

Josef Martinez, Franco Escobar and Hector Villalba scored for Atlanta United to lead a 3-0 rout of the Supporters' Shield-winning New York Red Bulls in the opening leg of the Eastern Conference final Sunday.

"We've just raised our game," captain Michael Parkhurst said. "We've raised the energy, the desire, the fight."

Atlanta has a huge edge heading into the second leg Thursday night in Harrison, New Jersey. The winner of...