SANDY — A lesser player might not have answered the bell for the second half.

But for Alta quarterback Ammon Olsen, who had a disastrous first half in his team's 5A quarterfinal matchup with Davis on Friday, halftime gave him a chance to calm down during a talk with coach Les Hamilton, analyze what had gone wrong, and enjoy a fresh start as soon as the whistle blew to start the third quarter.

The break was just what Olsen needed, as he ultimately led the Hawks to a thrilling 21-20 win over the Darts, and a fourth consecutive berth in the 5A semifinals. The Hawks advance to play upstart Syracuse on the Rice-Eccles Stadium turf on Thursday at 2:30 p.m.

Alta trailed 20-7 at halftime, and Olsen accepted much of the responsibility for the deficit. He threw three interceptions in the first half, and lost a fumble on what appeared to be a broken play. His halftime numbers were ugly: 5-of-8 passing for 57 yards and four turnovers. It wasn't the type of performance you'd expect to see from one of the state's top quarterbacks.

"The first half I made a lot of mistakes," Olsen said. "I don't know what my deal was. I was out of it the first half. Their defense was quick. They were just mental mistakes on my part."

Olsen eventually did a 180-degree turnaround in the second half. He did throw his fourth interception of the game on Alta's opening drive of the third quarter, and normally sure-handed receiver Parker Webster lost a fumble to give the Hawks their sixth turnover on their next possession.

But enough was enough. Olsen directed an eight-play, 77-yard drive and finished it off with a 4-yard touchdown run on Alta's third possession of the third quarter.

"Ammon's a great kid," Hamilton said. "He's good enough to be able to sweep things under the rug and come out and have a great second half, which he did. He was fantastic."

The next time the Hawks got the ball, Olsen directed a nine-play, go-ahead scoring drive. He finished it off with a gutsy 4-yard touchdown strike to tight end Drake Eckholdt on a fourth-and-1 play. The touchdown and extra point by Vance "Moose" Bingham gave the Hawks a 21-20 lead.

Olsen combined with running back Alex Rivas to put the game away on Alta's final drive. The Hawks didn't give the ball back after getting it with 5:40 left. They ran 14 plays, with Olsen and Rivas keeping it on the ground for the majority of them. Webster also made a catch to convert a first down, and he picked up a first down on a 6-yard rush on a run-option punt play.

Olsen completed 13-of-19 passes for 228 yards. Rivas ran for 70 yards on 11 carries. Chase Herbert was Olsen's top target, as he caught six passes for 99 yards and a touchdown.