Coleman scored 19 of the Bears' final 24 points, including five free throws in the final 39 seconds, to give first-year coach Wyking Jones his first victory.
Mark Crowe, Donovan Fields and Jakub Niziol hit 3-pointers in the final 31 seconds to get the Mustangs close, but they never had possession with a chance to take the lead.
Center Kingsley Okoroh had 15 points and freshman Justice Sueing had 12 for the Bears (1-1), who shot 51 percent from the field and had a 31-18 rebounding advantage.
Lee, a 6-foot-11 senior, who sat out last season after transferring from Kentucky, also had 11 rebounds. His previous scoring high was 17, set in his first game for the Wildcats in 2013.
Marcellus Garrick had 19 points and Fields had 18 for Cal Poly (0-2), which lost at Stanford on Friday.
Garrick made all five of his 3-point attempts, Fields made 4-of-6 and Victor Joseph made 3-of-5 as the Mustangs made 16-of-28 3-point attempts, 10-of-14 while shooting 63 percent from the field in the second half.
California took control late in the first half, using a 24-12 run to take a 44-30 lead. Coleman had 10 points in that run, two 3-pointers and two layups. Sueing had 12 points and Coleman and Lee had 11 apiece at half.
Coleman made three 3-pointers and was 11-of-14 from the free throw line. He had a career-high 31 points in a 74-66 loss to Cal-Riverside on Friday.