"I think I showed I'm capable of leading this team to a national championship," Sexton said.
Rix sustained a medium-grade ankle sprain, according to trainer Randy Oravetz, when he planted his right foot to make a cut as he scrambled near the FSU sideline midway in the first quarter.
A limping Rix finished the series but was taken to the locker room for X-rays.
Enter Sexton, with 44 seconds left in the first frame and the Seminoles trailing 7-3.
"When Chris came back (in second quarter), he wanted to go in, but Randy felt like it wouldn't be wise,'' FSU Bobby Bowden said.
"I didn't think it was, either. And I wanted to see what Wyatt could do, anyway.''
Wyatt did just fine, surviving a nervous start.
He completed 17 of 26 passes for 162 yards. He threw the Seminoles' first touchdown pass this season on a perfect toss to Chauncey Stovall, who hauled the ball in full stride, after running past cornerback Justin Miller for a 47-yard score.
"We put Wyatt in pressure situations in practice,'' Stovall said.
"We let him know if Chris goes down, he has to step up in big game. And he came in (Saturday) and took charge.
"He was calm in the huddle. He made us laugh before he went out for the play. After the first couple of plays, he was settled in the pocket and it was time to play ball."
A smiling Sexton was greeted by a chorous of cheers as he left the field.
"They were bringing pressure from everywhere, making sure I was mentally prepared for the game and knew my sight adjustment and hot reads. Once I did that, I could start feeling comfortable and start picking them apart," Sexton said.
"I was real nervous at first but once I calmed down I felt like I managed the game pretty solidly. The guys were down in the huddle, not believing in themselves. I told them let's just do what we have to do and go execute."