Lacy's intensity was typical of an overall Utah defensive effort that resulted in three turnovers and overall plenty of short fields for the Ute offense.
One side of the ball fed the other as Utah limited Cal to six plays and 4 yards in the second quarter.
"We played well overall," Utah defensive lineman Joe Kruger said. "but [we] could have played better. But we got to the quarterback tonight."
Defensive line coach Chad Kauha'aha'a challenged his players, and they responded with four sacks by four different Utes, including Kruger.
The defensive pressure up front rushed California quarterback Zach Maynard, who threw an interception caught by Lacy which set up Utah's third touchdown.
Utah's second score was also the product of defense. Linebacker Jason Whittingham popped Cal receiver Chris Harper, knocked free the football.
Utah corner Reggie Topps scooped the ball and sprinted 17 yards for a touchdown. Star Lotulelei pounced on the Utes' second fumble recovery.
"The defense played well for three and a half quarters," Utah coach Kyle Whittingham said. "We got soft there at the end, but I'm very proud of the players and coaches. We worked and put a great game plan together."
Cal gained 167 yards in the fourth quarter when the game was far out of reach.
• Utah's defense forced three turnovers, including a fumble return for a touchdown by Reggie Topps.
• Joe Kruger, Reggie Topps, Tenny Palepoi and Dave Kruger recorded sacks for Utah.