Ross was the catalyst behind the Huskies' 26-6 run that erased a 47-37 deficit with 12:16 left and gave Washington (11-6, 4-1 Pac-12) its biggest lead at 63-53 on Ross' fifth 3-pointer of the night with 5:15 remaining.
Ross scored eight points during the run, and then for good measure added a step-back 3-pointer and an alley-oop dunk three-point play to give the Huskies an 11-point lead with 3:09 left.
Faisal Aden led Washington State with 18 points, but the Cougars (9-8, 1-4) went eight minutes of the second half with just one field goal.
If Ross' night wasn't impressive enough, the sophomore added 14 rebounds as the Huskies held a decisive 46-24 advantage on the boards. The performance by Ross was even more valuable since Washington was without starting guard C.J. Wilcox after an second MRI revealed a stress injury to a sore hip that's been bothering Wilcox for about a month.
Wilcox went through pregame warm-ups, but it was announced about five minutes before tip that he would not play. Wilcox was coming off a career-high 25 points Tuesday night in the Huskies' hard-fought 91-83 win over city rival Seattle.
Tony Wroten added 13 points for Washington, who remained a half-game behind Stanford and California in the Pac-12 standings. And both Bay Area schools make a visit to Seattle next week, giving the Huskies a chance at holding first place by the end of next weekend.
More nights like this from Ross would certainly help. He was a miserable 1 of 9 shooting in the first half and missed three of his first four shots in the second. Ross then made his next six shots and was 6 of 9 at the free-throw line. It was the finest performance by a Husky since Matthew Bryan-Amaning scored 30 last January against Arizona State.
Ross was also at the center of the moment when Washington's run began. Huskies coach Lorenzo Romar erupted with anger after Ross was called for an offensive foul, nearly ripping off his suit jacket and picking up his first technical foul of the season from referee Mike Reed. Aden hit both free throws to give the Cougars a 47-37 lead with 12:16 remaining.
Then Washington's charge began.
Ross tipped in a drive from Wroten that was perilously close to basket interference. Gant hit an open 3 from the corner and after Aden scored, Aziz N'Diaye scored on the interior and Wroten converted a three-point play in transition to cut the Washington State lead to 49-47 with exactly 10 minutes left.
Washington State's next possession ended in a tie-up that had Cougars coach Ken Bone lunging on the floor to try and call a timeout before the tie-up and slipping to the deck, his dress shoes leaving a black streak on the floor.
But it was Washington that kept streaking. Wroten added another free throw and dunks on consecutive possessions from Gant the second on a perfect lob from Abdul Gaddy gave Washington the lead, its first since 2-0. N'Diaye scored again and another set of 3s from Gant and Ross gave Washington a 60-51 lead before Aden's two free throws finally slowed the streak.
Washington ended up shooting 38 percent, but that was after an awful 29 percent and eight turnovers in the first half. Washington had just two turnovers after the break.
Brock Motum added 17 points for Washington State, but 13 of those came in the first half. The Cougars used a 2-3 zone to frustrate the Huskies for most of the first half, but they eventually had to come out of the zone as Ross and others heated up from the perimeter. Washington's athleticism then took over in the closing minutes.