An injury to Quinn Ewers ended the Arch Manning show in Texas.

The boy from one of the most famous football families scored immediately.

Manning threw four touchdowns and ran 67 yards for another score after stepping in for Ewers in the second quarter to lead the No. 2 Longhorns to a 56-7 victory over UTSA on Saturday night.

Texas (3-0) led 14-0 when Ewers left the field with what coach Steve Sarkisian called a pulled abdominal muscle. Manning threw a 19-yard touchdown to DeAndre Moore on his first play and then broke off a long sprint for another touchdown on Texas’ next possession as several UTSA (1-2) defenders chased him.

“When the adrenaline kicks in, it helps you run a little faster,” Manning said.

Manning threw a 51-yard touchdown to Isaiah Bond on Texas’ first series of the third quarter, making it 35-7. His next throw was a 75-yard touchdown to Ryan Wingo. He completed 9 of 12 passes for 223 yards and left the game early in the fourth quarter after his final touchdown pass to Johntay Cook II.

“It helps when you have great players and good coaches around you,” Manning said.

The five-star recruit with NFL family pedigree is the most prolific backup quarterback in the country. With sharp passes and an unexpected burst of speed, Manning showed he could actually live up to the hype.

Manning is the son of Cooper Manning, the grandson of former NFL quarterback Archie Manning and the nephew of Super Bowl-winning quarterbacks Peyton and Eli Manning. And if Ewers is out for an extended period, Texas still has time to develop Manning as a starter before the schedule becomes significantly more difficult.

Texas hosts Louisiana-Monroe next week and then opens its first SEC game at home against Mississippi State on Sept. 28. The Longhorns will then have a week off before their annual rivalry with Oklahoma.

Texas made no immediate announcement about how long Ewers, who entered the game as the favorite for the Heisman Trophy, will be out.

Sarkisian determined that Ewers’ injury was not caused by contact.

“It remains to be seen how serious this is. We do not believe it is a structural or defect issue,” Sarkisian said.

Ewers had just completed a 49-yard pass to tight end Gunnar Helm with a deep throw and then handed off to Quintrevion Wisner before waving to the team’s medical staff and laying on his back.

Ewers eventually left the field, but pulled his shirt over his face as he entered the medical tent. He stood on the sidelines in civilian clothes during the third quarter.

Manning called Ewers one of his best friends on the team, noting that the two are roommates when the Longhorns sleep together the night before games.

“I just learned so much from him,” Manning said. “He was my man and I hope he’s OK.”

Sarkisian praised Manning’s demeanor in that moment.

“It’s hard when you have a backup who doesn’t have a lot of experience. Arch was our third man last year,” Sarkisian said. “There’s nothing like being in the game. Playing in front of 105,000 people is not the easiest thing. I’m really proud of Arch.”