STANFORD, Calif. — Stepfan Taylor, Tyler Gaffney and Anthony Wilkerson powered seventh-ranked Stanford to a school-record 446 yards rushing to blow past No. 22 Washington 65-21 on Saturday night.The running backs gave Heisman Trophy hopeful Andrew Luck some rest as the Cardinal (7-0, 5-0 Pac-12) extended the nation’s longest winning streak to 15 games. Taylor ran for 138 yards, Gaffney 117 yards and Wilkerson 93 yards to break the previous team mark of 439 in a victory over Oregon State in 1981.Facing the first ranked opponent of the season, Stanford pounded the Huskies (5-2, 4-1) in a critical Pac-12 North matchup.Chris Polk ran for scores from 46 and 61 yards in the first half to keep Washington close early. He finished with 144 yards rushing as the Cardinal’s defense clamped down.Luck threw for 169 yards and two touchdowns and completed 16 of 21 passes but was overshadowed — for once — by a running game that has quietly been among the nation’s best the last few years. No matter what happens next week at Southern California, the victory also almost guarantees that Nov. 12 matchup against Oregon at Stanford Stadium will decide the North’s representative in the inaugural Pac-12 championship game.Taylor and Gaffney each ran for a touchdown and Wilkerson had two. Wilkerson’s 38-yard scamper late in the fourth quarter gave Stanford the most yards rushing in a single game, eclipsing a 439-yard mark set in a victory at Oregon State in 1981.