Chase Brown became the first Illinois running back to rush for 100-plus yards in five straight games, Tommy DeVito passed for 329 yards and three touchdowns and the Fighting Illini blanked Chattanooga 31-0 on Thursday night.
Illinois improved to 3-1 and is off to its best start since 2015.
Brown capped a five-play, 64-yard scoring drive with a 9-yard touchdown run after the defense forced Chattanooga (3-1) into a three-and-out on its first drive.
He finished with 108 rushing yards on 20 carries and currently leads all FBS rushers with 604 yards through four games.
The closest the Mocs came to scoring came early in the second quarter when they drove to the Illinois 16-yard line. Jartavius Martin picked off a Preston Hutchinson pass in the end zone to end the Mocs' threat and preserve a 10-0 lead.
The Illini recorded their first shutout since a 2015 win over Western Illinois.
Chattanooga went just 4 of 14 on third downs and gained 142 total yards. Illinois piled up 502 yards of offense.
Hutchinson was sacked four times and completed just 6 of 18 passes for 49 yards with two interceptions.
Illinois nearly quadrupled Chattanooga's total first-half yardage, 332 yards to 84 yards, and led 24-0 at intermission.
Williams' 63-yard touchdown off a screen pass made it 31-0 with 4:56 left in the third quarter.
DeVito became the first Illinois quarterback to pass for more than 300 yards in a game since Brandon Peters threw for 369 yards at Michigan State in 2019.
Ailym Ford rattled off runs of 39 and 32 yards for the Mocs' biggest gains of the night. He finished with 93 yards on 17 carries.
Andrew Southard missed a 43-yard field-goal attempt early in the third quarter after Ford's 32-yard run took the Mocs into Illini territory.
Caleb Griffin kicked a 34-yard field goal to put Illinois up 10-0 in the first quarter.
Bret Bielema returns to his old stamping grounds when the Illini play at Wisconsin on Oct. 1.