Sanchez completed 20 of 37 passes for 332 yards and two touchdowns.
Sanchez told reporters after the game he had missed playing.
“I kept telling myself when I was out, that if I get a chance to be out there, I don’t ever want to be out again until I retire,” he said.
It was the first time Sanchez passed for at least 300 yards without an interception.
“For his first time out, I thought he did a good job,” Coach Chip Kelly said.
Matt Barkley replaced Sanchez late in the fourth quarter with the Eagles leading, 45-21.
His one pass fell incomplete.
Questions about USC? Email me at LNThiry@gmail.com or tweet @LindseyThiry and I will answer select emails in a weekly USC Now mailbag.