The Huskies played an inspired final game of the regular season, putting together an effort that was consistent only in rare spurts during the conference season.
Williams-Goss received plenty of help. Andrew Andrews had 16 points and Mike Anderson added 15 in his final home game.
Washington (16-14, 5-13 Pac-12) was 15-4 after winning at Colorado on Jan. 22, and appeared bound for the NCAA Tournament. The Huskies proceeded to lose their next seven games and 10 of 11 as injuries and player discipline left the Huskies short-handed. Included in that skid was a 21-point loss to the Utes in Salt Lake City.
For at least an afternoon, that troubling six-week stretch where the Huskies tumbled to near the bottom of the Pac-12 standings was forgotten.
"I think from the start, I thought we came out and played with a lot of energy, a lot of confidence," Williams-Goss said.
Jernard Jarreau scored a career-high 14 for Washington including three 3-pointers, after entering the game with two 3s in his career.
Utah (23-7, 13-5) lost for the third time in five games and will now be the No. 3 seed for next week's Pac-12 Tournament in Las Vegas after finishing in a tie with Oregon. Delon Wright led the Utes with 21 points.
Jakob Poeltl of the Utes had 18 points, but was held to three in the second half. Poeltl was 7 of 7 from the field in the first half but was taken out of the game by Washington in the final 20 minutes.
The loss dropped Utah into a tie with Oregon but the Utes lost the head-to-head tiebreaker having lost to the Ducks in their only regular season meeting.
"We lost some pride and hopefully it's a nice little wake up call for a bunch of guys that have been drinking some Kool-Aid that think we're a lot better than we are," Utah coach Larry Krystkowiak said. "We're making the game way too complicated."
On the verge of watching Utah run away, the Huskies surged into the lead midway through the second half behind a 22-8 run. Washington pulled even at 45 on Anderson's driving layup and his two free throws on the next possession gave Washington its first lead since 30-29 late in the first half. Utah went more than 6 minutes without scoring before Dakarai Tucker's fastbreak layup off a Washington turnover with 9:11 left.
Jordan Loveridge added a banked 3-pointer but the Washington run continued. Jarreau sandwiched two 3-pointers around Andrews' driving layup, the second 3 giving Washington a 55-50 lead with 6:44 left.
Loveridge later hit another 3 with 3:13 left to cut Utah's deficit to four, but Williams-Goss answered with another floater and hit the key 3-pointer as the shot clock was about to expire. Washington was 8 of 8 at the free throw line in the final minute.
FIGURE THIS OUT:
Washington will go to the Pac-12 Tournament owning three victories this season over teams that were ranked in the AP Top 15 at the time of their matchup. Washington beat then-No. 13 San Diego State and then-No. 15 Oklahoma in December.
Utah: The Utes entered the regular season finale as one of two teams nationally not to allow an opponent to score more than 72 points in a game. Ball State had scored a season-high 72 on the Utes in the season opener.
Washington: The Huskies trailed at halftime for the 14th straight game. ... The Huskies held a 17-4 advantage on rebounds in the second half.
Utah: The Utes will have a bye on the first day of the conference tournament and play Thursday evening.
Washington: The Huskies will play in the opening round of the conference tournament on Wednesday as the No. 11 seed against Stanford.
Official Box Score:
Nigel Williams-Goss and Mike Anderson: