The half-marathon world record holder Kiplimo crossed the finish line one minute and 31 seconds ahead of Amos Kipruto of Kenya, while Kenyan Alex Masai was third in 2:04:37.
Kiplimo, who finished second in his marathon debut in London this year, broke away by the 30-kilometre mark and had built a nearly one-minute cushion with five miles to go.
He peeked over his shoulder a few times during the last mile of the race but had nothing to worry about as he jogged through the final straight all by himself and sat down in sheer exhaustion a few metres after the finish.
Feysa, who finished third on the podium in Tokyo, appeared emotional through the final mile and fell to her knees after crossing the line in 2:14:56, while her compatriot was second in 2:17:18.
Tanzanian Magdalena Shauri took the third spot on the podium in 2:18:03.
Feysa ran the last five miles of the race on her own, thriving in Chicago's pristine, sunny conditions to shave more than two minutes off her personal best.