Beane made three 3-pointers to help the Salukis (9-2) shoot 50 percent (9 of 18) from beyond the arc. Sean O'Brien scored 15 points with five blocked shots while Tyler Smithpeters and Rudy Stradnieks both had 11 points.
J-Mychal Reese led North Texas with a career-high 25 points.
Both teams struggled early, combining for eight points through the first four minutes. The Salukis went on a 13-0 run - including a pair of 3-pointers by Smithpeters - while Oakland (2-7) missed seven consecutive shots and five free throws. Southern Illinois led 32-18 at the break.
The lead reached 20 points early in the second, but Oakland used a 17-6 run to get it back to five on Ja'Michael Brown's 3-pointer with 7:50 left. But Southern Illinois responded with back-to-back 3s by Beane and pushed its lead back to 14 with 4:07 to go.