Backup quarterback Noah Fifita led the go-ahead drive in the fourth quarter and helped Arizona kill the final three-plus minutes as the visiting Wildcats outlasted Stanford 21-20 on Saturday.Arizona (3-1, 1-0 Pac-12) lost starting quarterback Jayden de Laura in the final seconds of the third quarter, when he sustained an ankle injury on a scramble while trying to get out of bounds.Fifita, a redshirt freshman playing his first meaningful snaps of the season, entered on the next possession, leading a nine-play, 67-yard drive. The march was capped by a 2-yard rush from DJ Williams that put the visitors on top 21-17 with 7:42 to go.Stanford (1-3, 0-2) reached the Arizona 21 on the ensuing possession, but Jacob Manu sacked Ashton Daniels for a loss of 6 yards on second-and-10 and Daniels was penalized for an illegal forward pass on third-and-16. The Cardinal settled for a 46-yard field goal by Joshua Karty to make it 21-20 with 3:08 left.Arizona took over at its 11 on the final possession, with Fifita completing two passes for 14 yards as the Wildcats ran out the clock.Fifita was 4 of 4 for 47 yards in the fourth quarter, and he ran twice for 9 yards. De Laura wound up 14 of 26 for 157 yards and a touchdown.