LMU (3-0), which had trailed by five with 1:04 to play, called a timeout in the waning seconds to set up a play for Gabe Levin. His dunk was partially blocked and Dickinson made the putback for a 73-72 lead with 6 seconds left. Ireland, who was in the top 10 free throw shooters in the West Coast Conference last season, hit two free throws after a 49er turnover.
Long Beach State's LaSalle McKay missed a 3-pointer at the buzzer.
Dickinson and Ireland each finished with 14 points and Evan Payne led the Lions with 18.