Bridges made 11 of 13 field goal attempts and 7 of 7 free throws, as the Spartans shot 68.2 percent from the field. Spartans freshman forward Jaren Jackson Jr. powered for a career-high 21 points, 11 rebounds and six blocks.
Joshua Langford added nine points and Cassius Winston recorded eight assists but also committed eight turnovers for Michigan State (18-3, 6-2 Big Ten).
The Spartans' shooting percentage was its best since 2004, but they also had their highest number of giveaways in 13 years.
"The turnovers were inexcusable," Michigan State coach Tom Izzo said. "Even though Cassius got nailed with some early, it was some of bigs' fault early, too. They did not release pressure, things we talked about. Give them credit, give us blame but big win for us."
Sophomore forward Kipper Nichols poured in a career-high 27 points for Illinois (10-11, 0-8), which has lost six straight and remains the only Big Ten team without a conference victory. Nichols' previous high was 17 points.
Trent Frazier supplied 13 points, and Leron Black added 12 for the Illini.
The Spartans shot 78.9 percent and outrebounded the Illini 17-5 in the first half yet led by just seven, 39-32, at halftime. Turnovers kept Illinois in it, as Michigan State committed 15.
When the Spartans managed to hold onto the ball, Bridges was unstoppable. He scored 17 points while making all six of his field goal attempts.
A 9-2 Spartans run early in the second half stretched the advantage to 12, 48-36. Winston recorded assists on all four baskets during that stretch. Nick Ward converted a pair of layups, Langford hit a 3-pointer and Bridges hammered home an alley-oop dunk.
Lourawls Nairn Jr.'s fast-break layup with 11 minutes remaining extended the lead to 18 at 62-44. Illinois trailed by double-digits until a 9-0 run, sparked by Frazier, cut the Spartans' lead to 77-69.
--Field Level Media
Michigan St | Illinois | |
Miles Bridges 31 | Scoring | Kipper Nichols 27 |
Cassius Winston 8 | Assists | Da'Monte Williams 4 |
Jaren Jackson Jr. 11 | Rebounds | Greg Eboigbodin 3 |
Jaren Jackson Jr. 11 | Free Throws Made | Kipper Nichols 4 |
Miles Bridges 1 | Steals | Mark Smith 2 |
Jaren Jackson Jr. 6 | Blocks | Mark Alstork 2 |
Team | Points | FG% | 3PM-3PA | FTM-FTA | Assists | Rebounds | Blocks | Steals | Turnovers |
Michigan St | 87 | 68.2 | 4-9 | 23-28 | 15 | 37 | 9 | 5 | 25 |
Illinois | 74 | 43.1 | 8-28 | 10-14 | 12 | 12 | 2 | 8 | 10 |