Updated

Iowa State coach Paul Rhoads won't spend much time dwelling on the blowout loss to Baylor.

Instead, he'll pause to consider his next move at quarterback.

Bryce Petty threw for 343 yards and two touchdowns, the Baylor defense came within a minute of its first Big 12 shutout against a shuffling pair of quarterbacks and the No. 12 Bears tied a school record with their 10th straight win, beating Iowa State 71-7 on Saturday night.

Iowa State (1-5, 0-3 Big 12) replaced starter Sam Richardson with redshirt freshman Grant Rohach while Baylor pulled away in the second quarter. Richardson came back in the second half, but it didn't matter much.

The Cyclones had nine first downs and three turnovers, although they spoiled Baylor's shutout with 47 seconds left on a 27-yard pass to DeVondrick Nealy from Rohach, who replaced Richardson again in the second half.

"Neither was the winning edge, and there's 10 other guys out there on the field, too," said Rhoads, adding that he went into the game thinking Rohach would play. "There's a lot that wasn't done. It's not just that quarterback position."

The late Iowa State touchdown opened the door for Baylor (6-0, 3-0) to get its fourth 70-point game of the season when Corey Coleman returned the ensuing kickoff 97 yards — the second special teams score of the game for the Bears.

"We have a complete team," said Petty, who has the Bears off to their best start since 1980 on a winning streak that matches one from 1936-37. "We've got to keep doing it."

Antwan Goodley had 11 catches for 182 yards and two touchdowns, and Lache Seastrunk had 112 yards rushing a week after his streak of 100-yard games ended at eight.

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," 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.

Wimberly went 18 yards on Rohach's first play, but that was the only first down before a quick 17-point burst to finish the half by the Bears, who came in leading the nation at 715 yards and 63 points per game.

Richardson and Rohach combined for just 133 yards passing with an interception apiece and five sacks between them. Richardson went down three times, and Baylor had 10 tackles for loss.

The Cyclones finished with just 41 yards rushing because they had 47 yards in losses. They had 174 yards total offense, with 57 coming on the late scoring drive.

"It was very apparent, the first two drives nerves kind of got to me," Rohach said. "As the game went on, I got more reps, they slowed down for me, which is nice. I didn't like the outcome."