DENVER – An upset by seeding but certainly not by how the game played out.

No. 11 Gonzaga dominated most of the way, shut down Seton Hall standout guard Isaiah Whitehead and powered to a 68-52 first-round victory in front of 19,500 Thursday at the Pepsi Center.

The Zags (27-7) looked very much like a team that has done this before, and for good reason. They’ve made 18 straight NCAA tournaments and they’ve won their opening-round game in the last eight.

Gonzaga will meet third-seeded Utah (27-8) on Saturday. Tip time will be 30 minutes after the conclusion of Arkansas-Little Rock and Iowa State, which tips at 3:10 PDT.

Sixth-seeded Seton Hall (25-9), which starts five sophomores, hadn’t been to the NCAAs in a decade and showed its inexperience. Head coach Kevin Willard picked up a technical foul for protesting a no-call in the second half. Whitehead was tagged with a Flagrant 1 foul in the first half.

“We kept getting stops,” coach Mark Few said. “Our first-shot defense was off the charts. About the only way they had success, especially in the first half, was either off (GU) turnovers and/or second shots.”

Whitehead had a miserable night, scoring just 10 points on 4-for-24 shooting. The sophomore guard, hounded by Eric McClellan and Silas Melson, missed all 10 of his 3-point attempts. He had scored at least 20 points in Seton Hall’s last seven games.

Gonzaga kept Whitehead in check without allowing his teammates to pick up the slack.

“We felt we could help off their bigs and plug the lane on penetration,” said assistant coach Tommy Lloyd, who compiled the scouting report. “Stay in front of their guards and make them shoot contested shots. We felt like they would settle for a bunch of jump shots and that would hopefully help us with the rebounding.

“There might be something to this: They might be a pretty good defensive team,” added a smiling Lloyd. “The numbers say it and they’re starting to do it consistently.”

Domantas Sabonis, battling an illness, posted his 21st double-double with 21 points and 16 rebounds.

“It’s been a tough week for me. I have a fever and sore throat going on but I just tried to battle through it,” Sabonis said. “It was a very physical game. Their bigs were physical with me. I kind of like that and it played to my advantage.”

Kyle Wiltjer, limited to 12 first-half minutes due to two fouls, added 13 points and seven rebounds. The guard line continued its strong play as starters McClellan, Kyle Dranginis and Josh Perkins combined for 24 points, 13 rebounds and eight assists. Melson came up big at both ends of the court, especially in the first half as the Zags built a 10-point lead. He added eight points and seven boards.

Gonzaga led by 15 early in the second half but the Pirates kept it interesting. They closed within 54-48 with 6:50 left but Sabonis connected on a jump hook and Perkins made a timely steal that resulted in the freshman guard hitting a pair of free throws.

McClellan’s free throw bumped Gonzaga’s lead to 60-48 with 4:22 left and the Pirates turned it over when Michael Nzei inexplicably stepped over the end line before inbounding the ball.

“We were just being too fast on offense and not being patient like we usually are,” Seton Hall guard Derrick Gordon said. “This (first-round game) was quite new for everybody.”

The Bulldogs overcame 20 turnovers, which led to 16 Pirate points, by dominating the boards 48-34 and holding Seton Hall to a season-low 52 points. The Pirates made just 32.3 percent of their shots and finished 8 for 21 at the free-throw line.

“This is probably my worst shooting performance,” Whitehead said. “I had some good looks but just couldn’t knock them down.”

The Zags were up five early but the Pirates nosed in front at 21-20. Melson buried a corner 3-pointer and Sabonis added a pair of inside buckets to fuel a 7-0 run.

Gonzaga led 35-25 at half. The Pirates missed their last 15 field-goal attempts of the half.