Ennis was 6 of 9 from the field, including 5 of 8 from 3-point range, and matched his team-leading scoring average. Jennings pulled down seven rebounds for the 49ers (11-8, 7-1 Big West), who shot 57 percent from the floor and 58 percent from beyond the arc.
Irvine stayed close throughout the first half and trailed just 37-35 after Alex Young's 3-pointer a minute after halftime. But the Anteaters ran out of gas later in the second half, and Long Beach State's 15-3 run turned a 59-52 lead into 74-55.
Long Beach State has won its last five meetings with UC Irvine.
Maryland point guard Melo Trimble has withdrawn from the NBA draft and will return to College Park for his junior season, sources told ESPN.
Louisville's Chinanu Onuaku, who recently underwent a medical procedure to correct a heart rhythm issue detected during the combine, will keep his name in the NBA draft pool.
Andrew White III will return to the Nebraska men's basketball team next season after removing his name from the NBA draft.