The Arizona Wildcats started out the first half just fine today.

It was the second half that was a problem. A big problem.

After California took a 50-40 lead on a 17-2 run to start the second half, the Wildcats never recovered and suffered a surprising 77-69 loss at McKale Center. Most of Arizona's close calls and losses this season have come after struggling early in games.

Allen Crabbe had 31 points to lead the Bears, while Justin Cobbs had 21 for Cal. Mark Lyons had 16 points to lead Arizona in scoring but was 5 of 14 from the field.

Cal shot 58.8 percent from the field, by far the biggest percentage UA has given up all season. The next-worst defensive effort was against Oregon's 48.1-percent shooting on Jan. 10.

The loss snapped Arizona’s four-game winning streak and a chance to make a big jump in the Associated Press Top 25 poll after four of the six teams ahead of the Wildcats lost over the past week. Arizona is now 20-3 overall and 8-3 in the Pac-12, back in a first-place tie with Oregon and UCLA.

Cal improved to 14-9 and 6-5.

After Lyons and Cobbs traded three-pointers late in the second half, Crabbe drove the baseline for a basket that gave Cal a 73-69 lead entering the final minute. Arizona missed several shots on its ensuing possession while Cal’s Justin Cobbs made a layup for a 75-69 Bears lead and a pair of free throws by Cobbs later sealed it at 77-69.

Up 38-33, Arizona dug itself a hole in the second half when the Bears went on a 17-2 run immediately after halftime, including 15 unanswered points.

Over that period, Cal made all five field goals it took while UA made just 1 of 9.

 Arizona answered with 9-2 run, and cut Cal's lead to 52-49 but the Wildcats were never able to recapture the lead.

In the first half, the Wildcats used defense and 11 points from Solomon Hill to take  a 38-33 halftime lead over California.

The Wildcats forced six Bears turnovers in the first eight minutes and held Cal to 1-of-6 three-point shooting for the half.

However, Crabbe had 12 points on 6-for-8 shooting. Crabbe kept Cal in the game late in the first half with six points over three minutes to help the Bears cut UA’s lead to 30-27 with three minutes left.

Hill and Lyons later hit three-pointers to keep UA's halftime margin to two baskets.

UA struggled initially, falling behind 6-2 early but received a three-point play from Kaleb Tarczewsi to make it 6-5 while Arizona later went on a 10-2 run to take a 25-17 lead. 

Arizona forward Grant Jerrett returned three minutes into the game after missing UA’s game with Stanford last Wednesday because of a stress reaction in his left foot.

UA coach Sean Miller had said Jerrett would play if he was able to practice fully with the Wildcats all weekend without experiencing any pain.