Trent Frazier scored a career-high 22 points and Leron Black added 20 to lead Illinois to a 70-64 win over Missouri on Saturday night.
The Illini (9-5) have won five straight games in the annual pre-Christmas showdown.
Kassius Robertson paced the Tigers (10-3) with 22 points. Jordan Barnett added 19 points and 10 rebounds.
Illinois leads the overall series 25-12 in games played in St. Louis.
Mark Smith added 11 points for Illinois, which won its first six games before losing five of its next seven, and Michael Finke scored 10.
Illinois used runs of 9-0 and 10-0 to roll out to a 19-5 lead.
Missouri, which had a five-game winning streak snapped, missed 10 of its first 12 shots and committed 14 turnovers on its first 29 possessions over the initial 16-plus minutes.
The Tigers got to within 66-62 in the final minute.