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For the second match in a row, Red Bulls had a goal disallowed, before Tim Parker scored a 90th-minute consolation, Atlanta holding on through its 3-0 first leg lead to qualify for the championship-deciding match, which it will host at  Mercedes-Benz Stadium on 9 December (AEDT)

 Atlanta will be joined in the championship game by Portland Timbers, which managed to secure a 3-2 win over Sporting Kansas City at Children's Mercy Park in the second leg of the Western Conference Finals.

That was enough to send Portland into a second MLS Cup after the first leg finished 0-0.

Sporting opened the scoring in the 20th minute as Daniel Salloi tucked away a cross from Diego Rubio.

But the Timbers struck twice early in the second half to take control of the tie, including a stunning equaliser from Sebastian Blanco.

Blanco received a pass from Jorge Villafana on the left before cutting inside and unleashing an incredible strike into the top corner from 30 yards.

Diego Valeri was stunned by Blanco's brilliant goal, before he put the Timbers ahead in the 61st minute.

Blanco's pass put in Jeremy Ebobisse, who was denied by goalkeeper Tim Melia, but Valeri was on hand to head in the rebound.

Gerso Fernandes' goal with nine minutes remaining made for a tense finish, but Valeri sealed Portland's win deep into additional time.