Petty, the nation's leader in passing efficiency, was 23 of 31 without an interception and ran for a touchdown before he and the rest of the starters were pulled early in the fourth quarter with the Bears leading 51-0 on the way to their 17th win in their last 18 home games.
"You don't have to tell them much," Iowa State coach Paul Rhoads said. "They know they just got whipped and I know I just got whipped."
Playing their first game as the highest-ranked team in the Big 12, the Bears got their offense cranking again a week after needing two touchdowns in the fourth quarter to pull out a 35-25 win at Kansas State.
Now they go back to Kansas to face the Jayhawks next weekend, already eligible for a bowl game for a school-record fourth straight year.
"That's a big deal," Baylor coach Art Briles said. "Our goal has been 'six after six' since last spring, and our players accomplished it."
Baylor's first big play was actually a backward pass from Petty to Levi Norwood, who pulled up and threw a left-handed floater that Jay Lee had to wait for and thus was pulled down from behind after a 41-yard gain. Goodley got the Bears' first touchdown on a 4-yard catch three plays later.
The Bears scored again a minute later after just the second lost fumble of the season for the Cyclones at their 29. Aaron Wimberly dropped the ball as he was thrown to the turf by Byron Bonds, and Eddie Lackey recovered.
After a 26-yard pass to Tevin Reese, who had 105 yards receiving, Seastrunk scored for a 14-0 Baylor lead.
The Bears went up 20-0 on a 90-yard drive to a 21-yard field by Aaron Jones, and the Cyclones looked like they were in trouble on the next possession when Rohach came out to take the first snap of his career.