One former USC quarterback started and another finished in the
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.
His one pass fell incomplete.