EUGENE, Ore. — UCLA stayed undefeated Saturday, holding off No. 13 Oregon 17-15 after the Ducks’ seven turnovers repeatedly stalled their offense and a late two-point attempt failed. Wayne Knight supplied both Bruins touchdowns, rushing for 103 yards on 22 carries and catching a 9-yard scoring pass from backup quarterback Ty Dieffenbach early in the fourth quarter. UCLA improved to 5-0 overall and 1-0 in Big Ten play; Oregon fell to 3-2 and 1-1. The Ducks cut the deficit to 17-15 with 2:16 remaining on Brock Thomas’ 44-yard touchdown pass to Evan Stewart. A UCLA facemask penalty moved Oregon’s two-point try closer, but the Bruins stopped running back Jordon Davison short of the goal line. Oregon got the ball back with less than a minute left, but fumbled during its final drive as time expired. UCLA’s victory came with a change at quarterback. Nico Iamaleava left late in the first half with a lower-leg injury and did not return after the break. He completed 10 of 17 passes for 162 yards, with two interceptions. Dieffenbach threw for 43 yards and the touchdown to Knight. Oregon also turned to a backup. Dylan Raiola started in place of Dante Moore, who remained in concussion protocol after being injured in the Ducks’ Sept. 26 game against USC. Raiola completed 6 of 18 passes for 43 yards and threw two interceptions before Thomas took over in the fourth quarter. The turnover trouble shaped the game from the first half onward. After Iamaleava fumbled at UCLA’s 1-yard line, Oregon recovered and Davison scored on a 1-yard run to take a 7-3 lead. In the third quarter, Raiola lost a fumble, and Knight followed with a 35-yard touchdown run to put UCLA ahead 10-6. Knight’s run was his 10th rushing touchdown of the season. UCLA added its final touchdown after Dieffenbach found Knight in the end zone. Oregon’s Gage Hurych made a 26-yard field goal with 5:16 remaining, setting up the tense finish. The teams combined for 10 turnovers, and UCLA entered the game with 10 interceptions on the season, the most in the nation. The loss dealt another setback to Oregon’s hopes of reaching the College Football Playoff. The Ducks host Nebraska next Saturday, while UCLA is set to host Wisconsin.