The Bulldogs (34-1) are still dancing — on a day when the tournament's top overall seed, Villanova, was shown the door, that's all that matters.
Still, Gonzaga will leave Salt Lake City with a pair of victories and plenty more questions after two uneven performances at Vivint Smart Home Arena.
The Bulldogs' offense sputtered through the first half of their opener against South Dakota State before the Zags pulled away in a 20-point victory on Thursday.
On Saturday, Gonzaga looked every bit deserving of its No. 1 seed for the first 20 minutes, as the Bulldogs overwhelmed the Wildcats with size and athleticism. With Gonzaga's 7-footers, the hulking Przemek Karnowski and the towering Zach Collins, patrolling the paint, the Wildcats settled for many of their looks from the perimeter. The Cats could never make the Bulldogs pay: Northwestern was a dismal 1 for 11 from beyond the arc in the first half Saturday.
When Williams-Goss picked the pocket of Northwestern's Sanjay Lumpkin with about 3 minutes before halftime, the Gonzaga guard strolled the three-quarters of the court alone for a two-handed slam that put his team on top 34-14.
It felt as if a blowout were in the works. Still, in the locker room during intermission, Gonzaga coach Mark Few warned his club about the Wildcats, who were making Northwestern's first trip to the tournament in its 78-year history.
"They just had kind of a spirit of a winner," Few said.
They certainly tested Gonzaga's spirit down the stretch.
The Wildcats picked up their intensity on both ends of the floor. And when forward Vic Law Jr.'s put-back dunk popped the rim with 5:31 to play, the Zags' lead was down to 5. Northwestern had momentum and a chance to make it a single-possession game 30 seconds later, but the referees missed a crucial call, allowing Collins to reach through the basket to block a shot at the rim.
Northwestern coach Chris Collins came out on the court to protest a call that the officials would later admit they blew, picking up a technical foul. The four-point swing all but shut the door.
"The way we fought, it was great," Collins said of his team. "And we fought to the very end. We just came up a little bit too short."
Northwestern got 20 points and seven assists from point guard Bryant McIntosh and another 18 points from Law. For Gonzaga, Williams-Goss finished the game with 20 points and eight rebounds. Collins added 14 points and four blocks off the bench.
Gonzaga will move on to face No. 4-seed West Virginia, and the Bulldogs still have their sights set on Phoenix.