The Bears (9-0, 6-0), even without several key offensive players, stretched their school-record winning streak to 13 games. They are the outright Big 12 leader after No. 23 Texas absorbed its first conference loss earlier in the day, and are one of six undefeated FBS teams.
Shock Linwood, effectively the Bears' third-string running back, ran 29 times for 187 yards and a touchdown while Devin Chafin, another redshirt freshman, had 11 carries for 100 yards and two TDs. Levi Norwood had TD catches of 40 and 58 yards, and also returned a punt 58 yards for a score.
Texas Tech (7-4, 4-4) lost its fourth straight game since a 7-0 start for first-year coach Kliff Kingsbury, who was the Red Raiders' starting quarterback when Baylor coach Art Briles was the running backs coach at Tech from 2000-02.
Baylor played its first game since Briles this week got a new 10-year contract through the 2023 season, and was down 14-0 after 8 minutes before getting on a roll. The coach is in his sixth season with the Bears, who had 12 consecutive losing seasons since the inception of the Big 12 when he arrived.
Next week, the Bears play at No. 12 Oklahoma State (9-1, 6-1), which won 38-13 at Texas hours earlier.
And they have a chance to move a spot in the new BCS standings on Sunday. The Bears were fifth last week, behind Stanford - which lost for the second time this season, 20-17 to Southern California on Saturday night.
Baylor played without its top two running backs, Big 12 rushing leader Lache Seastrunk (groin) and Glasco Martin (knee), and 103-yard-a-game receiver Tevin Reese. All got banged up in the Bears' 41-12 win over Oklahoma nine nights earlier, Reese the most serious with a dislocated right wrist that required surgery and will force him to miss at least the rest of the regular season.
The Bears still surpassed their FBS-best scoring average of 61 points that was already on pace to break a major college scoring record. They had 675 total yards, only 11 below their nation's best average.
Petty was 17-of-31 passing for 335 yards, and put Baylor ahead to stay when he hit wide-open Antwan Goodley for a 31-yard TD pass and a 21-20 lead with 4 seconds left in the first quarter. Goodley's Big 12-best 11th TD catch came immediately after K.J. Morton intercepted a pass.
Baker Mayfield, starting as Tech's quarterback for the first time since its fifth game, completed 28 of 51 passes for 314 yards and four touchdowns. His only pick came when he threw a pass right into the chest of the leaping Morton.
Bears kicker Aaron Jones became the NCAA career leader for extra points with nine more, pushing his career mark to 260. The previous record was the 253 by Art Carmody of Louisville from 2004-07, which Jones passed with his three in the first quarter. Jones has made 175 in a row, the NCAA's longest active streak.
Texas Tech led 14-0 after standout tight end Jace Amaro had touchdown catches on the Red Raiders' first two drives. There was a 6-yard TD on a halfback pass from Kenny Williams on the 15th play of a game-opening 75-yard drive before Amaro got wide open for a 20-yard score from Mayfield the next time they had the ball.
Amaro took a crushing hit from Ahmad Dixon while holding on for an 18-yard catch to the 4, two plays before Mayfield's 3-yard TD to Jakeem Grant with 4:28 left in the first half got the Red Raiders within 28-27.
After staying down on the field for several minutes, Amaro got up and walked to the sideline on his own power, though slowly. He did get back in the game, but didn't have another catch. He finished with four catches for 55 yards.