Keaton Grant scored 22 points, Nemanja Calasan added 17 and Purdue used a 20-3 second-half run to rally past Illinois 74-67 on Saturday.
The Boilermakers (13-5, 4-1 Big Ten) trailed by nine points in the first half and again early in the second before the Illini (9-10, 1-5) went cold. Robbie Hummel, scoreless in the first half, had eight of his 13 points during Purdue's big run, and a basket by Calasan gave the Boilermakers their first lead of the game, 43-42.
A basket by Hummel and six straight points by E'Twaun Moore then helped push Purdue's lead to 51-43 and the Illini never recovered.
A 3-pointer by Trent Meacham pulled Illinois within 58-55 with 5 minutes to go, but Calasan hit three free throws, Grant added two more and then hit a clinching 3-pointer with under 2 minutes remaining.
Grant's 22 points matched the most by any Purdue player all season.
Shaun Pruitt and Brian Randle led Illinois with 15 points each, while Meacham added 11.
Purdue never led in the first half, missing nine straight shots over the opening 5 1/2 minutes before the initial wave of substitutions helped produce three quick scores by the Boilermakers.
Each of Illinois' first six baskets was by a different player, including consecutive 3-pointers by Chester Frazier and Meacham for a 14-6 lead. Meacham hit his second 3-pointer during a flurry of long-range shots by both teams over the next few minutes, and two straight layups by Pruitt gave the Illini their biggest lead at 21-12.
Purdue came within five points several times before halftime, but Illinois responded each time, including a last-second 3-pointer by Frazier for a 35-27 lead at the break.
Illinois matched that early in the final period at 40-31 before a rebound tip by Hummel, his first basket of the game, started Purdue's comeback.