Deion Lavender had 17 points, shooting 5-of-7 from 3-point range, Anthony Beane scored 16 and Jordan Caroline added 14 points and 11 rebounds for Southern Illinois (10-16, 3-10). Beane scored 14 of his 16 points in the second half.
The lead changed seven times in the second half, including a dunk by Deane which gave Southern Illinois a 56-55 advantage with 6:43 left.
A layup by James 33 seconds later sparked a 6-0 run and gave Loyola the lead for good.
Jalen Pendleton's free throw with 2:22 remaining pulled SIU within 64-62, but the Salukis missed their final three shots and committed two turnovers down the stretch.