A Juan Pablo Angel header briefly tied the match, 1-1, but Rolfe scored twice more, and he and his teammates ran rampant to add goals by Brian McBride and substitute Daniel Woolward before Macoumba Kandji tapped a ball home in the final minutes.
The result guarantees Kansas City a wild-card spot and leaves the door wide-open for D.C. United to grab the eighth and final place in the very last game of the season.
New York can still get in, but needs help from Columbus. Kansas City, which is currently tied with New York (39 points) in seventh place overall, beats the Red Bulls in the first tiebreaker, head-to-head results, and thus qualifies even if loses to the Revs on Saturday. Regardless of what the Wizards do, D.C. (37 points) will edge New York by a point by beating the Crew Sunday. That match kicks off at 5 p.m. ET.
Rolfe snapped home a header from a Stephen King cross in the 11th minute, chested down a partial clearance and volleyed a spectacular goal in the 38th, and ran onto a Cuauhtemoc Blanco pass in the 44th to stick home his third goal.
He might have been a shade offside when Blanco played him the ball in tight quarters to send him in alone against keeper Danny Cepero, but that's about the only bad break that befell the Red Bulls during a ruthless Fire display.
Chicago blew the game open in the 53rd minute when Rolfe tricked his way through midfield and played a diagonal ball out wide that Diego Gutierrez centered and McBride pounded home at the far post. A cross from the right flank by Rolfe fell perfectly for Woolard to head in his first MLS goal with 15 minutes left.
Chicago (13-10-7, 46 points) finishes second even if New England beats Kansas City to tie the Fire on points because Chicago swept the season series between the teams, 3-0. That Eastern Conference semifinal series against the Revs begins next Thursday at Gillette Stadium.
The fifth-place team in the East, which could be D.C. United or New York, will "cross over" to play Western Conference champion Houston in the first round. Eastern champ Columbus will play the fourth-place Eastern team, the identity of which won't be known until early Sunday evening, Eastern Daylight Time. With a win, D.C. finishes fourth. Otherwise, that spot goes to K.C.
Oct. 23 in Bridgeview, Ill.
Chicago 5 New York 2. Goals: Rolfe (King, Mapp) 11, Rolfe 38, Rolfe (Blanco) 44, McBride (Gutierrez, Rolfe) 53, Woolard (Rolfe) 75; Angel (van den Bergh) 32, Kandji (Richards, Leitch) 88.
Chicago -- Busch, Prideaux, Soumare, Conde, Gutierrez, King, Pause, Rolfe (Nyarko, 82), Mapp (Woolard, 74), McBride (Banner, 85), Blanco.
New York -- Cepero, Leitch, Boyens, Cichero, Goldthwaite (Sassano 46), Pietravallo (Kandji 46), Rojas (Richards, 65), Stammler, van den Bergh, Magee, Angel.
Yellow cards: Chicago -- Gutierrez 72; Pietravallo 28, Goldthwaite 42.
Referee: Baldomero Toledo