Garris also had 10 assists for the Illini. Chris Gandy added 14 points and 10 rebounds as Illinois outrebounded Iowa, 45-29.
Illinois (7-4 Big Ten, 17-6 overall) held Andre Woolridge, the Big Ten's leading scorer, to 12 points. Guy Rucker, Iowa's 6-9 center, made most of Iowa's inside shots and led the team with 16 points.
The Hawkeyes dropped to 7-3 in the Big Ten and 16-6 overall.
Sixty-two fouls were called and 87 foul shots were taken at Bloomington.
Indiana 93, Ohio State 76
Ohio State coach Randy Ayers and guard Damon Stringer were ejected with two technical fouls each, and Knight had one technical.
At one point, Knight left the bench and walked off the court into a hallway. Later, he took a seat on the front row of the bleachers behind the Indiana basket.
"I was tired of watching the game from where I was," Knight said. "I wanted to see if the view improved. It didn't.
"I may sit up in the balcony the next time."
A.J. Guyton scored a career-high 24 points as the Hoosiers (5-6, 18-7) avenged a loss at Ohio State (4-7, 9-11) nine days earlier.
"It's a win. That's what we got out of it," Knight said. "We had lost three games in a row. ... You've got to get something out of it."
Purdue 77, Michigan State 62
Chad Austin scored 27 points and Brad Miller added 18 points and 10 rebounds for Purdue at East Lansing.
The Boilermak-ers (8-3, 13-8) have won six of their last seven games and find themselves in the thick of the race for a fourth-straight Big Ten title and an NCAA tournament bid.
"We've got the heavyweight belt - we've had it the last three years - and it's ours until somebody takes it away from us. We've started winning and some of our young kids are playing a little beyond their years," Keady said.
Michigan State (4-6, 11-8) has lost its last five games.
"To say we're struggling is an understatement," Spartan coach Tom Izzo said.
Wisconsin 56, Northwestern 44
The game at Evanston featured the two Big Ten teams with the worst scoring average, and Northwestern (1-10, 6-16) and Wisconsin (6-5, 12-7) lived up to their reputations.
The combined 100 points was lowest by two teams in the league this season.
Ty Calderwood scored five of his team-high 12 points during a key 14-5 run in the first half and Wisconsin held Northwestern to just seven baskets in the second half en route to victory.
"We knew it would be extremely difficult to pull away from Northwestern," said Bennett. "But I'm extremely pleased with what occurred tonight."