Atlanta United took complete control of the Eastern Conference Finals in MLS after a 3-0 first-leg win over the New York Red Bulls on Sunday.
Josef Martinez, Franco Escobar and Hector Villalba scored in Atlanta's convincing victory against the Supporters' Shield winners at Mercedes-Benz Stadium.
Martinez took his tally to a record 34 goals this MLS season with the opener just after the half-hour mark.
The Venezuelan brilliantly brought down a cross from Jeff Larentowicz before producing a composed finish to make it 1-0.
Bradley Wright-Phillips thought he had equalised early in the second half, but his effort was ruled out after a video review.
The forward's strike from inside the area beat Brad Guzan, but it was ruled Alex Muyl was obstructing the goalkeeper's view in an offside position.
The Red Bulls were punished in the final 20 minutes, leaving them with work to do in the second leg on Thursday.
Escobar put away Julian Gressel's cutback to make it 2-0 before Villalba came off the bench to strike from 20 yards in additional time.
In Portland, the Timbers and Sporting Kansas City played out a 0-0 draw in the first leg of the Western Conference Finals.
Jorge Villafana hit the post for Portland, who had a goal ruled out for offside in the second half.