Utah needed 76 seconds to score on USC.

The visiting Utes opened Saturday’s top-25 battle with the ball. Tailback Ja’Quinden Jackson picked up 13 on possession-and-10, then he picked up 9 on the next play. Utah offensive coordinator Andy Ludwig then dialed up a play Utah narrowly missed on a week ago.

In the win over Cal, Utah put Sione Vaki in the backfield and sent him on a wheel route down the right sideline. Quarterback Bryson Barnes overthrew what would have been a touchdown.

Saturday against USC, Utah sent him on a wheel route down the left side.

Barnes hit him in stride and Vaki raced for a 53-yard touchdown.

Last week, Vaki emerged as an option in the backfield and ran for 158 yards and two touchdowns on 15 carries.

His rushing output was the most by a defensive back in recorded Pac-12 history. Vaki, the Utes’ starting safety, also became the first Utah defensive back to rush for two touchdowns in a game since Eric Weddle had a pair at Air Force on Nov. 18, 2006.

Utah said during the week that Vaki’s role would only grow.

“That package will continue to expand,” coach Kyle Whittingham said. “He is the perfect guy for that role and going forward you’re going to continue to see him.”

USC might want to key on him a little better.