Brandon Paul scored 17 points, Tracy Abrams added 13 and the No. 10 Illini pulled away late to remain unbeaten with a 66-53 victory over Eastern Kentucky on Sunday night.
In a game between undefeated teams, the Illini led by 11 early but needed a late 12-2 run to gain control and help Groce become only the second coach in Illinois history to win his first 12 games. Groce matched the school record for the best start by a first-year coach set by Fletcher Lane in 1907.
"I usually wear navy blue, gray or black," said Groce, who wore an orange sport coat for the first time. "Then coach (Lou) Henson and I talked this summer. I told him when he came back from Las Cruces (N.M.), I'd wear an orange coat out of respect for him."
Groce stood for pictures before the game with Henson, the legendary Illini coach who made the orange wardrobe his trademark.
Illinois, off to its best start since opening the 2005-06 season 15-0, was sluggish on offense, going 6 of 23 from the 3-point line with 20 turnovers.
"Obviously, we didn't make as many 3s as we'd like," said Groce. "Sometimes that happens. That's when you have to rely on defense and rebounding."
Illinois never trailed thanks to holding Eastern Kentucky (9-1) to 36-percent shooting overall. The Colonels shot 27 percent from the 3-point line and 38 percent from the free throw line.
"I'm really, really proud of our effort," Groce said. "Our effort for 40 minutes was outstanding. We had a nastiness on the defensive end. We packed our defense and had it ready to go."
The Illini also controlled the boards with a 42-23 advantage.
"I'm going to be driving home in my car proud of these guys for their effort and toughness," Groce said. "When you defend like that, rebound and play hard, it's fun to coach and watch them."
Joseph Bertrand chipped in with 11 points for Illinois.
Corey Walden scored 21 points and Glenn Cosey had 11 for the Colonels, who came in riding the school's best start in 66 years. Eastern Kentucky hadn't won nine straight games since the 1964-65 season.
Illinois stretched its regular-season, non-conference winning streak at home to 34 games, but the Illini have been unable to duplicate their strong road performances at home. Illinois rolled through the Maui Invitational, winning its first title there to break into the Top 25, and an 11-point win at Gonzaga last weekend lifted the Illini into the top 10.
But the team's play has been underwhelming during the home schedule.
The Illini raced to a 17-6 lead but had trouble putting away the Colonels. The Illini were 2 of 13 from the 3-point line with 10 turnovers in the first half. Eastern Kentucky scored 11 points off those turnovers to keep it close.
"At halftime, I really felt we'd win the game," Eastern Kentucky coach Jeff Neubauer said. "Our defense was good enough to win the game."
Had it not been for the poor shooting, Eastern Kentucky might have taken the game to the wire.
"We've been much better defensively," Neubauer said. "We've invested so much time in our defense. I've not done a good enough job with our offense. It showed up tonight."
The Colonels cut the margin to 42-38 on a three-point play by Walden, but moments later Abrams scored seven points during the key surge for the 54-40 lead.