NORMAN, Okla. -- Baker Mayfield passed for 300 yards and two touchdowns and ran for another score to help No. 11 Oklahoma defeat Baylor 45-24 on Saturday.

Sooners coach Bob Stoops said Mayfield is playing better than a year ago, when he finished fourth in the Heisman Trophy balloting. He said Mayfield has improved as he has become more comfortable with offensive coordinator Lincoln Riley's system and receiver Dede Westbrook.

"He was fourth in the Heisman last year, so why wouldn't you expect him with another year to be better," Stoops said. "Do we expect? Yes, we do. And watching him from a year ago, having a full year under his belt with coach Riley and these other receivers, and the emergence of Dede -- yes, we expect him to be looking like this."

The Sooners won their seventh in a row overall and 15th straight in Big 12 play. Joe Mixon had 187 yards from scrimmage and Samaje Perine ran for 100 yards and two touchdowns after missing three games with a pulled muscle in his right leg for Oklahoma (8-2, 7-0 Big 12, No. 9 AP).

Baylor (6-3, 3-3; No. 25 AP) had hoped to bounce back after last week's 62-22 loss to TCU. Instead, the Bears are on their first 3-game losing streak since the middle of the 2012 season.

Baylor quarterback Seth Russell severely dislocated his left ankle and was carted off the field with 5:48 left in the third quarter. He passed for 148 yards and ran for 70 before getting injured, but he threw two interceptions and lost a fumble.

THE TAKEAWAY

Baylor: The Bears continued to fall apart. Their collapse started with a loss to Texas, got much worse against TCU, and now, things look bleak with Russell out. Russell missed much of last season with a broken neck. Backup quarterback Zach Smith completed 6 of 15 passes for 144 yards and a touchdown. The Bears will need to hope Russell's injury isn't as serious as it looked.

Oklahoma: Oklahoma's defense was solid for the third straight week after giving up 59 points and 854 yards against Texas Tech. The Sooners gave up three points against Kansas, then 24 against Iowa State the next game. Baylor gained 504 yards, but Oklahoma's defense forced three critical turnovers. Linebacker Jordan Evans led the way with two sacks and two interceptions.

POLL IMPLICATIONS

Baylor: The Bears' school-record streak of 60 consecutive AP poll appearances, which Baylor says is the fourth-longest active streak in FBS, will likely end.

Oklahoma: The Sooners, who were unranked heading into Big 12 play, could move higher in the AP Top 10 and position themselves to move into the College Football Playoff picture. Oklahoma was 12th in the AP poll at the same point last year.

UP NEXT

Baylor hosts Kansas State next Saturday.

Oklahoma travels to West Virginia next Saturday. The game against the 16th-ranked Mountaineers (No. 11 AP) provides the Sooners a chance to prove themselves against a high quality opponent.