Southern Illinois scored the final four points of the first half and the first nine points of the second to go ahead 34-16. Indiana State never mounted a challenge from there as the Salukis extended their lead to as much as 23.
Desmar Jackson had 16 points, Olaniyan scored 12 and O'Brien added 11 for SIU (7-15, 3-6 Missouri Valley). O'Brien and Olaniyan each had 12 rebounds.
Southern Illinois made up for 2-of-12 3-point shooting by shooting 52 percent overall and 25 of 38 on free throws. Indiana State was only 11 of 22 at the free-throw line.
Guard Naz Mitrou-Long, whose 2015-16 season ended in December due to hip problems, has been granted a hardship waiver for the coming season, Iowa State said.
As the Sooners look to life without superstar Buddy Hield and his sidekicks, it's clear their unseasoned players will need to grow up fast.
The Central Intercollegiate Athletic Association says it won't move its headquarters, its basketball tournament or other conference championships from North Carolina, despite