Derek Dimke kicked a go-ahead 21-yard field 20 win over Western Michigan on Saturday to remain undefeated.
The Illini (4-0) easily survived a final Broncos drive in the last 1:05 of the game after they were stopped on 4th-and-4 at the Western Michigan 32.
The Broncos (2-2) didn't have any remaining timeouts and only made it to the Illinois 41. Alex Carder was sacked for a loss of seven yards, running time off the clock, and completed two final passes for 20 yards before it ticked to zero.
Troy Pollard rushed for 133 yards, Nathan Scheelhaase passed for 133 with a touchdown and Dimke kicked three field goals for Illinois.
Carder passed for 306 yards and two touchdowns for Western Michigan, which built a 13-10 lead at halftime on his touchdown pass to Chleb Ravenell late in the second quarter.
Jordan White caught 14 passes for 132 yards and a touchdown for the Broncos.
Illinois head coach Ron Zook, after seeing his team climb back in the second half, said he was somber with them in the locker room.
"A lot of people may not agree with this, but sometimes you have to go through games like that. There are a lot of times that teams would have lost that game," said Zook. "I think if you go back and look at the 2007 year (when) we went to the Rose Bowl, you remember that Ohio State did exactly the same thing to us. We learn from it.
"We told them all week long that this is a good football team, and it is a good football team. Everyone saw that it is a good football team. Offensively, even though we did not score a lot of points, we took care of the football and kept the defense off the field (in the second half). It was hard for them to score when they did not have the football."
Illinois scored 10 points in the third quarter to take the lead and improved to 3-1 in the all-time series, avoiding a second straight loss after Western Michigan earned a 23-17 win the last time the teams met in 2008.
"We're all disappointed because as much talk as they had about Illinois coming into this game, we stayed toe-to-toe the whole time and we left 10 points out there. We had a guy open in the end zone and unfortunately we over shot him, and we missed two field goals and maybe that made the difference there at the end," said Western Michigan head coach Bill Cubit.
"You never know. You can talk all you want, but our kids fought and played hard. Did they out-physical us at the end? Probably. But during the game I thought our kids did a pretty good job"
Aaron Winchester's 30-yard return on the game's opening kickoff gave Western Michigan good field position, but a short drive ended in John Potter's missed 44-yard field goal attempt.
Later, Scheelhaase hooked up with tight end Evan Wilson for an 11-yard score to cap an eight-play drive and give Illinois a 7-0 lead.
Winchester took the ensuing kick back 22 yards and Western Michigan used 18 plays to pull within 7-3 on Potter's 26-yard field goal in the final minute of the first quarter.
Potter missed a 49-yarder early in the second after Jason Ford fumbled deep in Illinois territory, but the Illini were stuffed on 4th-and-goal from the one- yard line at the other end. Donovonn Young had sparked the drive with a 59- yard run on the first play, but Jay Prosch couldn't carry it over the line.
Carder was intercepted three plays later by Terry Hawthorne and Illinois cashed in the turnover on Dimke's 39-yard field goal for a 10-3 lead.
Another long Western Michigan drive -- this one 13 plays -- ended in Potter's 24-yard field goal inside four minutes before halftime.
The Illini punted, and Western Michigan took a 13-10 lead into halftime after Carder hit Ravenell on the right side and he cut inside past Supo Sanni for a 35-yard touchdown.
Scheelhaase was intercepted at the goal line by Justin Currie as time expired in the second quarter.
"We don't take anybody lightly and Western Michigan was a great opponent," said Pollard. "They came out and did some great things; they played hard and played well. It was pretty tough."
Illinois opened the third quarter with a 10-play drive capped by Young's 14- yard touchdown run to take a 17-13 lead. Dimke kicked a 35-yard field goal later in the quarter for a seven-point lead.
Western Michigan scored on the ensuing drive to tie it, with Robert Arnheim's leaping 34-yard catch near the right sideline setting up 1st-and-goal from the two. Carder and White connected on a seven-yard TD pass to tie the game at 20-20 early in the fourth.
Illinois then chewed up almost six minutes with an 11-play drive that ended in Dimke's 21-yarder for a 23-20 lead.
The Illini rushed for 296 yards, while the Broncos gained just 35 on the ground...Illinois was coming off wins over Arkansas State, South Dakota and Arizona state...Western Michigan, which lost to Michigan to open the season, had a two-game winning streak snapped.