Bradley Wright-Phillips got the visitors off to the perfect start in this winner-takes-all format, settling a perfectDamien Perrinelle chip into the area, beating goalkeeper Matt Lampson and poking home from close range.
Just past the 10-minute mark, there was more good news for the Red Bulls when Tyler Adams beat his defender on the right wing and curled a perfect cross in front of goal for Sacha Kljestan to slot home to make it 2-0.
Chicago took nearly half an hour to get its first legitimate chance, but Nemanja Nikolic's looping header from aLuis Solignac was easily handled by Luis Robles.
The Fire looked inspired after the break, coming close to finding a first goal twice at the start of the second half. Robles stopped a Chicago header from a corner on the doorstep right beforeMatt Polster narrowly missed to the left of goal with a shot from 20 yards out.
Daniel Royer would seal victory for the Red Bulls in the 70th minute, finishing a well-worked team move with a neat turn and strike to make it 3-0.
And New York poured salt in the wound as time was running out, Kljestan setting up Gonzalo Veron for a cheeky chip to make it 4-0.
The Red Bulls will face Supporters' Shield winning Toronto FC in the Eastern Conference semifinals.
Chicago 0-4 NYRB: BWP leads Red Bulls charge
The New York Red Bulls booked their spot in the Eastern Conference semifinals with a comprehensive 4-0 win in Chicago.