Jack followed up his debut in the backfield with 13 carries for 59 yards and four touchdowns as the 13th-ranked Bruins kept their Rose Bowl hopes alive with a 41-31 win over the Washington Huskies.
"It was a good win tonight against a really good football team," said UCLA head coach Jim Mora. "I'm proud of these guys. They continue to show grit and resilience and toughness and all those things that make a special football team."
UCLA (8-2, 5-2 Pac-12) pulled within a 1/2 game of Arizona State for the top spot in the Pac-12 South. The two teams will meet in a crucial bout in Pasadena on Nov. 23.
Brett Hundley passed for 159 yards and a pair of scores on 13-of-22 efficiency for the Bruins, who have won eight straight at home against Washington (6-4, 3-4).
Keith Price threw for 181 yards and a touchdown in the first half but took a big hit before halftime and did not return for the third quarter with a shoulder injury. Redshirt freshman Cyler Miles took over at quarterback and threw for 149 yards with a pair of touchdowns and two interceptions on 15- for-22 passing.
"That was a frustrating game for us," said Washington head coach Steve Sarkisian. "I will say that our kids fought hard. I thought Cyler came in and did a nice job."
Bishop Sankey carried 27 times for 91 yards and a score and Damore'ea Stringfellow hauled in eight passes for 147 yards and a touchdown.
Leading 34-24 entering the fourth quarter, the UCLA defense got a big stop when Miles' fourth down pass to Stringfellow fell incomplete. The Bruins took over in Washington territory and on the first play, Devin Lucien made a man miss after reeling in a short Hundley pass and outran the defense for a 40- yard touchdown.
Stringfellow's 14-yard TD reception less than two minutes later rounded out the scoring.
Earlier, UCLA benefited from a turnover on the third play from scrimmage when Austin Seferian-Jenkins caught a 5-yard strike from Price on third down but lost the football on his way to the ground. Anthony Jefferson recovered for the Bruins and after a quick review, the fumble was upheld.
UCLA capitalized on the short field when Jack carried a slew of defenders with him into the end zone on an 8-yard touchdown run.
Washington coughed the ball up again on its next series when Tahaan Goodman jarred the ball loose from Sankey. A facemask penalty on 3rd-and-10 resulted in a Bruins' first down, and Malcolm Jones busted a 30-yard run down to the Washington 4. Two plays later, Hundley's first completion of the contest was a short touchdown pass on play-action to defensive end Cassius Marsh.
Price completed all four of his throws on the next Washington drive, including a 50-yard bomb to Darrell Daniels down to the UCLA 2. Sankey took it in on the next play to put the Huskies on the board.
UCLA then ran off another 14 unanswered points on a pair of Jack 1-yard touchdown plunges to take a commanding 27-7 lead early in the second quarter.
Price threw a short touchdown pass to Jaydon Mickens at the 6:11 mark, and Travis Coons' 34-yard field goal resulted in a 27-17 UCLA lead at the break.
Bruins' return man Darren Andrews fumbled the kickoff to begin the second half and Cory Littleton recovered at the UCLA 27. Miles missed his first throw before completing two straight passes to Mickens. Sankey then carried four times down to the 1-yard line, and Miles found Seferian-Jenkins in the back of the end zone to cap 17 unanswered points for the Huskies.
But Jack's fourth score of the contest, which tied him for second all-time in program history for rushing touchdowns in a game, once again made it a two score game midway through the third.
Jack fell one touchdown shy of Maurice Jones-Drew's school record of five rushing scores, which he accomplished against Washington in 2004 ... Jack added five tackles while Marsh recorded five tackles to go with a sack ... UCLA improved to 39-30-2 all-time over the Huskies ... Bruins' receiver Shaquell Evans had two catches for 21 yards and has at least one catch in 25 straight games.
11/16 01:50:52 ET