Eugene Phelps and James Ennis had 14 points each for Long Beach State. The 49ers (20-7, 13-0), the defending Big West champions, will be the No. 1 seed in the conference tournament that begins March 8 in Anaheim, Calif.
Long Beach State had a 12-game winning streak snapped Saturday at Creighton.
Orlando Johnson led the Gauchos (15-9, 9-4) with 20 points. James Nunnally had 13 points and 12 rebounds for UCSB.