PROVO, Utah – Gonzaga set up for its final possession of an ugly first half, but the Bulldogs weren’t lined up correctly. Head coach Mark Few frantically shouted directions, but his players couldn’t hear him at the opposite end of the floor.

Kevin Pangos tried to throw a long cross-court pass and it was easily picked off, leading to yet another BYU basket at the other end.

When Anson Winder made the layup just before the buzzer sounded, Few shook his head in disbelief and began a slow walk to the locker room.

The Bulldogs coughed up 15 first-half turnovers, slipped into a 14-point deficit and couldn’t recover in an 83-73 men’s basketball loss to the Cougars in front of 19,257 Thursday at the Marriott Center.

“We were rattled, frazzled, played with no poise, no composure,” Few said. “Timeouts couldn’t stop it, substituting couldn’t stop it. BYU did a great job of coming out and playing with great energy and passion. … We haven’t been like that this year. That’s always the worry when you have two freshmen guards, but they were only part of the problem. It was everybody: seniors, juniors, all of them.”

Gonzaga brought out the best in BYU for the second time in roughly 11 months. The Cougars ended Gonzaga’s season last March with an 89-67 victory in the NCAA tournament. This time, BYU (19-6, 7-3 WCC) put a hurt on Gonzaga’s chances of winning a 12th consecutive WCC title. The 24th-ranked Bulldogs (17-4, 7-2) dropped farther behind Saint Mary’s (22-2, 11-0), which rallied past San Diego for a victory.

Gonzaga had a turnover on its first possession and nine in the first 11 minutes. The Zags reached their per-game average of 13 with 4:37 remaining in the first half when Guy Landry Edi drove into the lane and lost control of the ball.

The Bulldogs stayed close for a while, but they made just one of their last 14 field-goal attempts. BYU took full advantage of GU miscues – including on the final play of the half – and scored 18 of its points off turnovers en route to a 38-24 halftime lead.

“We weren’t in the right spot,” Few said. “Kevin just made a horrendous decision that kind of capped off the whole half. That’s something I’ve never seen him do in practice or a game all year. We probably had six or seven of those plays I haven’t seen in practice or games all year.”

BYU, behind Noah Hartsock’s hot shooting, led by 19 on three occasions in the second half. The Bulldogs cut the deficit to 11 and had a chance to make it single digits but Sam Dower misfired from 7 feet. Gonzaga was within 75-65 with 3:30 left and forced a BYU turnover. After a timeout, Gonzaga committed its 19th turnover when David Stockton’s pass was intercepted.

Hartsock made a pair of free throws with 2:55 left and the Cougars went on to record their biggest win of the season. BYU coach Dave Rose opted to start Winder over Brock Zylstra, and the 6-foot-3 freshman had 10 points, five assists and three steals, all in the first half.

“He responded really well,” Rose said. “Our game plan was to really attack them defensively. They’re a ball-screen team and when they bring those guys together, we took the post defender and guard defender and tried to run both at them.”

Gonzaga made 51.4 percent of its second-half shots, but the damage was already done. Dower had a team-high 15 points, Gary Bell Jr. scored 14 and Marquise Carter added 13, the most he’s scored since the season opener.

“I don’t think we’re coming into these road games with the right mindset,” Dower said. “We’re being the hunted instead of being the hunters. We have to change our mindset.”

Hartsock finished with 24 points and 14 rebounds. Matt Carlino added 18 points and Brandon Davies chipped in 15. The Cougars shot just under 50 percent from the field.

“We knew (Hartsock) was going to shoot those (jumpers),” Gonzaga center Robert Sacre said. “He’s a great player. He was a challenge in there. We’ll learn from this and get better.”

Percentages: FG .410, FT .714. 3-Point Goals: 3-19, .158 (Harris 1-1, Bell 1-4, Stockton 1-4, Landry Edi 0-1, Carter 0-1, Dower 0-1, Keita 0-1, Monninghoff 0-3, Pangos 0-3). Team Rebounds: 7. Blocked Shots: 3 (Sacre 2, Bell). Turnovers: 19 (Pangos 4, Carter 4, Harris 4, Sacre 2, Landry Edi 2, Stockton, Hart, Dower). Steals: 9 (Harris 2, Carter 2, Bell 2, Pangos, Hart, Stockton).

Percentages: FG .493, FT .706. 3-Point Goals: 3-12, .250 (Harrison 1-1, Carlino 1-2, Winder 1-4, Abouo 0-1, Cusick 0-1, Zylstra 0-1, Austin 0-2). Team Rebounds: 2. Blocked Shots: 3 (Hartsock 2, Davies). Turnovers: 12 (Davies 4, Carlino 3, Harrison 2, Abouo, Zylstra, Hartsock). Steals: 14 (Winder 3, Carlino 3, Cusick 2, Zylstra 2, Harrison, Austin, Hartsock, Davies).

Halftime—BYU 38-24. A—19,257.