The Trojans won their first Pac-12 game of the season Wednesday night, and California lost its first, as the Trojans defeated the Golden Bears, 77-69, at the Galen Center.
USC improved to 1-5 in conference games and 10-9 overall. Cal fell to 5-1 and 14-5.
The Trojans used a well-balanced attack — four of their players scored in double digits — and a drop in turnovers to take an early lead and then hold it for much of the game.
"We made a lot of shots early on, it gave us a lot of confidence," Enfield said.
USC was led by forward Nikola Jovanovic with 23 points, followed by Byron Wesley with 14 points and Pe'Shon Howard and Julian Jacobs, who each scored 12 points.
The Trojans committed 11 turnovers, but that was down from 18 in their previous home game against top-ranked Arizona.
Enfield had ascribed a good part of USC's poor start in Pac-12 play this season to the Trojans' inability to play well for the full 40 minutes.
But on this night the Trojans took a 41-32 lead into the locker room at halftime and didn't let up in the second half.
"We just gave effort for 40 minutes, which was nice to see," Enfield said. "It's a great win for our program and our team."
This game better resembled what USC had hoped for when Enfield was hired in April.
He arrived in Los Angeles with fanfare after two years as coach at Florida Gulf Coast University, where his fast-paced, high-powered offense was dubbed "Dunk City."
Instead, it had been rough sledding for the Trojans against their rivals in the Pac-12.
Within the Pac-12, USC entered the game 11th in total scoring, 10th in field-goal percentage, 11th in free-throw percentage and 12th in turnovers.
The Trojans also had suffered from an inability to stop teams from going on scoring binges, and for a moment Wednesday it appeared they'd have the same problem with Cal.
With about two minutes left in the first half, Cal went on an 8-0 run to cut USC's lead to 35-30. But the Trojans stopped the run there to take the halftime lead.
The Trojans play host to Stanford on Sunday and Cal plays UCLA the same day at Pauley Pavilion.