PROVO — Judging by the ubiquitous smiles and joyous celebration on the field and in the locker room after BYU’s 28-23 victory over Arizona Saturday night in Tucson, it’s pretty safe to say this team never came close to feeling that happy at any point during last season's dreadful 4-9 campaign.

Thanks in large part to a dominating, 21-point third-quarter barrage, the Cougars (1-0) won their season-opener — last year it wasn’t until late October that BYU finally earned its first win over an FBS opponent — against a Pac-12 foe on the road.

After the game, coach Kalani Sitake presented the game ball to first-year offensive coordinator Jeff Grimes, first-year offensive line coach Ryan Pugh and the entire offensive line, which set the tone for the win.

It was good for a lot of guys to come out here and make plays. – BYU quarterback Tanner Mangum

But amid the enjoyment of the moment, Sitake also stressed to his team the importance of humility and continuing to work hard.

Next Saturday (8:15 p.m. MDT, ESPN2) BYU hosts another Pac-12 opponent, California (1-0), in its home-opener at LaVell Edward Stadium. The Golden Bears held on to defeat North Carolina at home last Saturday, 24-17.

“(The celebration after beating Arizona) was good, especially with everything that happened to us last year. Rough season,” said linebacker Zayne Anderson. “So it feels good to get that first game. We’re humble. It’s just one game. We’re on to the next.”

“It definitely felt good to start the season off with a win,” said running back Squally Canada, who rushed 24 times for 98 yards and three touchdowns. “We’ve got to carry it over to next week and keep the momentum rolling.”

After a sluggish start in the first half, BYU’s offense erupted for three TDs in the third quarter as the offensive line imposed its will and manhandled the Wildcat defense.

“Our offensive line did a great job all night, moving the line of scrimmage, creating holes and playing physical,” said quarterback Tanner Mangum, who completed 18 of 28 passes for 209 yards and a touchdown. “Our running backs, like Squally, did a great job of hitting the hole hard and pushing for extra yards. It was a game-changer for us right there.”

The Cougars trailed 10-7 at halftime before they seized control. BYU not only outscored Arizona 21-0 in the third period, but the defense also held the Wildcats to a pair of three-and-outs. In the third quarter, BYU gained 169 yards, compared to 47 for Arizona, and had the ball for 11:24, compared to 3:36 for the Wildcats.

Going into the fourth quarter, the Cougars led 28-10.

“To come out that third quarter and start driving the ball and put points on the board was big,” Mangum said. “It gave us that momentum that carried us throughout the rest of the game. It gave us confidence and showed us what we’re capable of.”

Arizona outscored BYU 13-0 in the fourth quarter. Still, the Cougars had the ball 11:10 compared to 3:50 for the Wildcats in the final period.

On BYU’s final drive that began with 3:20 remaining in the game, the Cougars were clinging to a five-point lead. Canada ran five times for 28 yards, including a 9-yard run on third-and-7 to gain a game-ending first down. He had another long run earlier in the drive that was negated by an illegal formation penalty.

“We took it upon ourselves,” said offensive lineman Thomas Shoaf of that last drive. “Obviously, Squally and Tanner have to do their part. But we know that we have to win in the trenches. We can’t get those first downs if we don’t win in the trenches.”

“Ball security was the key. The offensive line had a great push,” Canada said. “(Wide receiver) Micah Simon had a great block that sealed the deal. The O-line opened up such big holes and the receivers blocked down field.”

The Cougar offense got a lot of contributions as 10 different players caught passes.

BYU tight ends Moroni Laulu-Pututau, Matt Bushman and Dallin Holker combined for five catches for 60 yards, including a 24-yard touchdown catch by Bushman.

BYU rolled up 183 yards on the ground, which included a flurry of fly sweeps. Six different players took handoffs Saturday.

“It was good for a lot of guys to come out here and make plays,” Mangum said.

Mangum outplayed preseason Heisman Trophy candidate Khalil Tate, who gained just 14 yards on eight carries and completed 17 of 34 passes for 197 yards and a touchdown.

“We knew (Arizona) would protect him and (Tate) wouldn’t be running as much. We contained him fairly well,” Anderson said. “Our coaches put a good game plan for these guys, and I felt like we followed through. We had some penalties that really cost us and some other mistakes that we’ll fix.”

Yes, the Cougars still have plenty of things to work on — on both sides of the ball.

“The penalties are something we need to improve on. We had some (pass interference) calls here and there. We had a boneheaded late hit,” Sitake said. “That shouldn't happen. It wasn’t a lack of effort. They played hard. We’ve got to play smarter. I’m not trying to be overly negative, but with the win now we can be and demand a little bit more from our guys.”

So on Labor Day, it’s back to work for BYU.

But as the Cougars can attest, it’s a lot better to go back to work coming off a win rather than a loss. Going to practice after a defeat was something BYU experienced much more than it wanted to after going 4-9 in 2017.

For now? The Cougars are unbeaten.

“It makes us excited,” Mangum said, “to get going next week.”