Ricky Council IV scored 18 points and Arkansas survived some anxious moments in the second half against an Illinois team that wouldn't go away, holding on to beat the Illini 73-63 in the first round of the NCAA Tournament on Thursday.
Devo Davis had 16 points for the eighth-seeded Razorbacks, who used relentless defense and rebounding to build big leads but couldn't get comfortable until the final minute.
Terrence Shannon Jr., held scoreless the first 16 minutes, finished with 20 points to lead the Illini (20-13).
Anthony Black intercepted Coleman Hawkins' cross-court pass and Council missed the fast-break dunk when he would have been better served to lay it in.
Council atoned for his missed dunk with a layup to end a 4-minute, 13-second scoring drought, and his two free throws with 1:18 left put the Razorbacks up 68-57.
Arkansas led by as many as 14 points in the first half and went to the locker room ahead 36-26 following a scrambling play under the basket where Kamani Johnson battled three Illinois players for a loose ball.
Arkansas' defense was on point from the outset, holding the Illini to 28% shooting in the first half and 38.5% for the game. The Hogs scored 19 points off Illinois' 17 turnovers.