Karisma Penn posted game-highs of 27 points and 19 rebounds as Illinois handed No. 6 Georgia its first loss of the season with a 70-59 victory at Assembly Hall.
Amber Moore and Adrienne GodBold each added 11 points for the Fighting Illini (7-5), who have won three of their last four.
Khaalidah Miller had 17 points and eight rebounds, while Jasmine James also poured in 17 points for Georgia (12-1), which was seeking its fifth 13-0 start during Andy Landers' 34 seasons as head coach.
After an early Jones jumper tied the game at 6-6, Moore, Taylor Tuck and Penn each connected on a 3-pointer during a lengthy 25-7 run that gave the Illini a 31-13 lead with a little over six minutes left in the first half.
Georgia, however, responded with a 9-0 push sparked by Miller's three-point play to cut its deficit to single digits and the Lady Bulldogs trailed, 36-29, at the break.
Illinois was able to keep Georgia at arm's length through the second half until a 13-4 run tied the game at 52-52 on a pair of James free throws.
But the Lady Bulldogs could not take the lead and after a Shacobia Barbee layup brought Georgia within 58-57 with 5:05 left in the game, Georgia would make just one more shot from the floor as Illinois closed out the contest with a 12-2 run to finish off the upset.