It was one of the few defensive mistakes Behrens and the Golden Bears made.
On a night when the offense for both teams was stagnant and sloppy, Behrens and the Bears' interior defense provided a much-needed boost and helped extend Cal's best start in 13 years.
Tyrone Wallace scored 12 of his 17 points in the second half including an emphatic dunk with 22.7 seconds left, Behrens added a career-high 12 points and eight rebounds, and Cal overcame a sluggish night offensively to beat Wyoming 45-42 on Wednesday night.
"Every game it feels like I have more confidence to do more stuff out there," Behrens said. "(Nance) stepped on my foot a little bit and it caught me off balance so I'll give him that. A little lucky for him."
The Bears needed some good fortune, too.
Cal (8-1) shot just 35.3 percent and rarely scored on consecutive possessions until pulling away late.
Wallace made consecutive 3-pointers and Behrens added a three-point play to give the Bears a 39-32 lead.
Nance scored seven straight for Wyoming but missed two jumpers in the final two minutes. Wyoming also turned the ball over twice late, leading to Wallace's slam and a game-sealing layup by Sam Singer.
"I don't think it was bad offense, both teams were good defensive teams," Cal coach Cuonzo Martin said. "They're normally that way and we're continuing to make progress defensively."
It was a bittersweet game in many ways for Cal.
The 42 points were the fewest the Bears have allowed in more than three years while their 45 marked their lowest point total in a win since beating Washington State 43-41 on Feb. 23, 2006.
"It probably wasn't one of your best outings offensively but it's one of those games you have to win," Martin said. "Offensively, they grind you out ... so it was a great lesson to learn from."
Nance had 13 points and 11 rebounds for Wyoming (8-2).
The Bears have won four straight since losing to No. 10 Texas 71-56 on Nov. 21 despite being without injured guard Jabari Bird for the last three games.
Both teams were sloppy in the first half and scored just 31 points combined.
Cal led only twice, shot 26.1 percent from the floor and missed five of their final six shots with two turnovers in the final seven minutes of the half.
Wyoming wasn't much better.
The Cowboys went 2 of 10 on 3-pointers and committed seven turnovers in the first half. Nance, who didn't score for the game's first seven minutes, had a pair of dunks including an emphatic one-hander that put Wyoming up 16-15 at the break.