Brigham Young Cougars running back Squally Canada (22) is knocked down during the game in Provo on Saturday, Sept. 8, 2018. BYU lost 21-18.
Jeffrey D. Allred, Deseret News
Brigham Young Cougars kicker Skyler Southham (20) watches the final minutes of the game in Provo on Saturday, Sept. 8, 2018. BYU lost 21-18.
Jeffrey D. Allred, Deseret News
California Golden Bears teammates Vic Wharton III (17) and cornerback Branden Smith (45) get tangled up in Provo on Saturday, Sept. 8, 2018. Brigham Young Cougars linebacker Zayne Anderson (23) was called for a penalty.
Jeffrey D. Allred, Deseret News
Brigham Young Cougars head coach Kalani Sitake protests the illegal touching call against the California Golden Bears in Provo on Saturday, Sept. 8, 2018.
Jeffrey D. Allred, Deseret News
Brigham Young Cougars wide receiver Dylan Collie (3) drops a pass against the California Golden Bears in Provo on Saturday, Sept. 8, 2018.
Jeffrey D. Allred, Deseret News
Brigham Young Cougars quarterback Tanner Mangum (12) is sacked by the California Golden Bears in Provo on Saturday, Sept. 8, 2018.
Jeffrey D. Allred, Deseret News
Brigham Young Cougars linebacker Butch Pau'u (38) watches the clock in Provo on Saturday, Sept. 8, 2018. BYU lost 21-18.
Jeffrey D. Allred, Deseret News
Brigham Young Cougars head coach Kalani Sitaki leaves the field with Brigham Young Cougars wide receiver Micah Simon (13) in Provo on Saturday, Sept. 8, 2018. BYU lost 21-18.
Jeffrey D. Allred, Deseret News
Morgan Clifford is held up and watches pregame with Luke Reece in Provo on Saturday, Sept. 8, 2018.
Jeffrey D. Allred, Deseret News
Brigham Young Cougars students cheer during pregame in Provo on Saturday, Sept. 8, 2018.
Jeffrey D. Allred, Deseret News
Brigham Young Cougars quarterback Tanner Mangum (12) runs onto the field during pregame in Provo on Saturday, Sept. 8, 2018.
Jeffrey D. Allred, Deseret News
Brigham Young Cougars quarterback Tanner Mangum (12) throws against the California Golden Bears in Provo on Saturday, Sept. 8, 2018.
Jeffrey D. Allred, Deseret News
The Brigham Young Cougars defense stop California Golden Bears tight end Ray Hudson (11) in Provo on Saturday, Sept. 8, 2018.
Jeffrey D. Allred, Deseret News
Brigham Young Cougars linebacker Sione Takitaki (16) celebrates a stop against the California Golden Bears in Provo on Saturday, Sept. 8, 2018.
Jeffrey D. Allred, Deseret News
Brigham Young Cougars kicker Skyler Southham (20) kicks a field goal against the California Golden Bears in Provo on Saturday, Sept. 8, 2018.
Jeffrey D. Allred, Deseret News
The Brigham Young Cougars defense stop California Golden Bears running back Patrick Laird (28) in Provo on Saturday, Sept. 8, 2018.
Jeffrey D. Allred, Deseret News
Brigham Young Cougars defensive lineman Corbin Kaufusi (90) rushes California Golden Bears quarterback Chase Garbers (7) in Provo on Saturday, Sept. 8, 2018.
Jeffrey D. Allred, Deseret News
Brigham Young Cougars linebacker Riggs Powell (44) and Brigham Young Cougars defensive back Dayan Ghanwoloku (5) defend California Golden Bears wide receiver Jeremiah Hawkins (10) in Provo on Saturday, Sept. 8, 2018.
Jeffrey D. Allred, Deseret News
Brigham Young Cougars quarterback Tanner Mangum (12) throws against the California Golden Bears in Provo on Saturday, Sept. 8, 2018.
Jeffrey D. Allred, Deseret News
Brigham Young Cougars defensive lineman Khyiris Tonga (95) blocks a pass by California Golden Bears quarterback Chase Garbers (7) in Provo on Saturday, Sept. 8, 2018.
Jeffrey D. Allred, Deseret News
Brigham Young Cougars place-kicker Rhett Almond (26) jumps for the ball before punting in Provo on Saturday, Sept. 8, 2018.
Jeffrey D. Allred, Deseret News
California Golden Bears cornerback Traveon Beck (22) celebrates his interception in Provo on Sunday, Sept. 9, 2018. BYU lost 21-18.
Jeffrey D. Allred, Deseret News
California Golden Bears quarterback Brandon McIlwain (5) scores on BYU in Provo on Sunday, Sept. 9, 2018. BYU lost 21-18.
Jeffrey D. Allred, Deseret News
Brigham Young Cougars defensive back Dayan Ghanwoloku (5) returns a fumble for touchdown against the California Golden Bears in Provo on Sunday, Sept. 9, 2018. BYU lost 21-18.
Jeffrey D. Allred, Deseret News
Brigham Young Cougars running back Brayden El-Bakri (35) scores against the California Golden Bears in Provo on Sunday, Sept. 9, 2018. BYU lost 21-18.
Jeffrey D. Allred, Deseret News

PROVO — Just like that, the high hopes surrounding the BYU football program the past week fell back to Earth with a resounding thud Saturday night at LaVell Edwards Stadium.

Coach Kalani Sitake warned that improving to 2-0 against California would be harder than it was getting to 1-0. And he was absolutely right.

The Cougars failed to build off the momentum generated in a season-opening win at Arizona as Cal earned a 21-18 victory before a crowd of 52,602.

BYU (1-1) was looking to re-establish its home field advantage after going 2-4 a year ago, but it suffered yet another defeat at Edwards Stadium.

The Cougar offense, meanwhile, looked a lot like last year’s version, featuring dropped passes, turnovers and difficulty finishing drives. BYU gained just 11 yards of total offense in the third quarter and finished with 287 for the game.

The Cougars didn’t score an offensive touchdown until the final minute of the game — on a one-yard touchdown pass from Tanner Mangum to Brayden El-Bakri. That, along with a two-point conversion, cut the deficit to 21-18.

But the Golden Bears recovered the ensuing onside kick and ran out the clock.

“We lost the game before that," Sitake said. "You’ve got to give credit to Cal. They made the plays to win," Sitake said. “We made way too many mistakes and didn’t have time to fix them by the end of the game. We have to be better. Effort is not enough to win games. We need to be more efficient as an offense and more disruptive as a defense."

"We finally figured it out late," said tight end Moroni Laulu-Pututau. "You can't do that against a team like Cal."

Cal (2-0) used two quarterbacks, Chase Garbers and Brandon McIlwain, and made plays at key times, as the Bears finished with 398 yards of total offense.

BYU’s defense and special teams forced three turnovers but other than a scoop-and-score by Dayan Ghanwoloku, the Cougars couldn’t capitalize.

Up 7-3 at halftime, the Bears added to their lead early in the third quarter thanks to a 52-yard touchdown pass by Garbers to Kanawai Noa, jumping out to a 14-3 lead.

On Cal’s next possession, BYU linebacker Butch Pau’u administered a big hit on Derrick Clark, who fumbled. Ghanwoloku grabbed the loose ball and raced 36 yards for the touchdown to cut the deficit to 14-10 with 10:07 left in the third quarter. It marked BYU’s first takeaway of the season.

“I was at the right spot at the right time," Ghanwoloku said. "I picked it up and ran into the end zone.”

The Cougars recorded an interception on Cal’s next possession when Isaiah Kaufusi returned a pick 20 yards. But BYU squandered that opportunity by punting again.

The Golden Bears all but sealed the win with a touchdown early in the fourth quarter with an 11-play, 85-yard drive that culminated with a two-yard touchdown run by McIlwain to make the score 21-10.

Ghanwoloku gave BYU another chance to score by recovering a muffed punt. The Cougars drove to the Cal 9-yard line but squandered that opportunity after a Mangum interception.

BYU’s offense got off to a strong start on its opening drive, advancing to the Arizona 32-yard line. But the drive stalled after a failed fourth-and-short attempt.

The Cougars encroached Cal territory again on their second drive but ended up punting.

Meanwhile, the Bears put together an 11-play, 80-yard drive that took 4:31 off the clock to take the lead. Cal converted on a fourth-and-5 play on the BYU 37 on a 12-yard pass from Garbers to Vic Wharton III. On the next play, Garbers connected with Laird on a 25-yard touchdown pass to give Cal a 7-0 advantage with 1:46 left in the first quarter.

On BYU’s first drive of the second quarter, the Cougars drove from their own 14-yard line to the Cal 19. But the drive, that lasted 6:15, stalled again, and BYU settled for a 36-yard field goal by Skyler Southam to cut the deficit to 7-3.

“We stalled on third downs and even fourth downs," Sitake said. "We should be able to run the ball and get a first down.”

The next time the Cougars got the ball, Dylan Collie dropped a long pass from Mangum that would have put BYU deep in Cal territory. Still, the Cougars reached the Bear 35 before an incompletion on third-and-5.

Instead of attempting what would have been a 52-yard field goal, BYU opted to go for it on fourth down again, resulting in Mangum being sacked for an 11-yard loss.

Late in the second quarter, the Cougars punted the ball. After a Cal player collided with his teammate, the return man, BYU’s Zayne Anderson scooped up the ball and ran into the end zone for a possible touchdown.

But the officials called illegal touching on the Cougars, giving the ball to Cal. The Bears ended up taking a 7-3 lead into the locker room at halftime.

At that point, BYU was outgaining Cal in total yardage, 193-124.

BYU travels to No. 5 Wisconsin next Saturday.