Nico Iamaleava threw for 194 yards and a touchdown, overcoming a pair of lost fumbles, as No. 6 Tennessee held on for a 25-15 win over No. 15 Oklahoma on Saturday in Norman, Okla.Volunteers coach Josh Heupel, who quarterbacked the Sooners to the 2000 national title as the Heisman Trophy runner-up, was honored before the game.Then Heupel’s defense dominated the Sooners as Iamaleava did enough to keep Tennessee (4-0, 1-0 SEC) undefeated.The Volunteers held Oklahoma to minus-4 yards combined in the second and third quarters as they steadily stretched their lead.The Sooners (3-1, 0-1) came alive in the fourth quarter, scoring a pair of touchdowns, but couldn’t cut their deficit below 10 points.Oklahoma starting quarterback Jackson Arnold was benched after going just 7-of-16 for 54 yards, giving way to freshman Michael Hawkins Jr., who didn’t do much better initially. But he led the fourth-quarter comeback attempt and finished 11-of-18 for 132 yards and a touchdown. He also ran for 22 yards on 12 carries.Bru McCoy finished with four catches for 92 yards for the Vols, while Dylan Sampson ran for 92 yards and a score.Tennessee outgained the Sooners 345-222.Iamaleava coughed up the ball twice in the second quarter, each time giving the Sooners the ball in Tennessee territory. But both times, the Volunteers’ defense quickly answered.