GLENDALE, Ariz. -- Heisman Trophy finalist Bo Nix and the high-flying Oregon Ducks made sure their last game as a Pac-12 team was one to remember.

Nix threw five touchdown passes, including four in the second quarter, and No. 8 Oregon steamrolled No. 23 Liberty 45-6 on Monday in the Fiesta Bowl.

Nix, in his final collegiate game after two seasons at Oregon and three previously at Auburn, tied a Fiesta Bowl record for touchdown passes in a game and was named the game's offensive MVP. The Ducks, who just missed the College Football Playoff after a three-point loss to Washington in the Pac-12 Championship game, scored 45 unanswered points after trailing 6-0 in the first quarter.

Nix completed 28 of 35 passes for 363 yards, and wide receiver Tez Johnson had 11 catches for 172 yards and was one of five receivers to catch a touchdown pass. Oregon (12-2) held previously undefeated Liberty (13-1) to its season low in points and rushing yards (168).

"I just think it speaks to the direction, the base that these guys have created for where we're headed and what we're about to do," Oregon coach Dan Lanning said, asked about winning 12 games going into the program's first year in the Big Ten next season. "They believed in what we wanted to accomplish."

Ducks running back Bucky Irving, who announced his intentions to enter the NFL draft but opted to play in the bowl game, rushed for 117 yards and a touchdown on 14 carries.

Liberty got the ball first and scored a touchdown in six plays. Quarterback Kaidon Salter had plenty of time to pick a receiver and found Bentley Hanshaw for a 17-yard touchdown pass.

The Flames didn't score again, as Salter was held to 126 passing yards. Oregon outgained Liberty 584-294 in total yards.

"Just keep on fighting, win or lose, we just wanted to fight, and we came out and it didn't go how we wanted it to, but nobody gave up on it," Salter said. "That's what made me so happy. Like, I'm proud of our team for not giving up."

The Ducks went ahead 10-6 early in the second quarter on Nix's 2-yard touchdown pass to Gary Bryant Jr., a play set up by Irving's 44-yard swerving run deep into Liberty territory.

Oregon's defense delivered hard hits and established control after Liberty's first possession, and the Ducks' offense got going as well. Dropped passes and batted balls didn't affect Oregon's ability to move the ball, and the Ducks went up 17-6 on Nix's 2-yard touchdown pass to tight end Terrance Ferguson with 7:13 to go in the first half.

By halftime, Oregon had a 31-6 lead. Nix's flip to Kenyon Sadiq for a 3-yard touchdown was set up by another of the Ducks' several explosive plays on the day, a 50-yard pass to Bryant.

Oregon stopped a Liberty drive before halftime with Steve Stephens IV's interception. Then Nix needed just five plays and 1:09 on the clock to find Traeshon Holden for a 17-yard touchdown with three seconds left.

The Ducks added two more touchdowns in the second half before Nix exited mid-drive in the fourth quarter to cheers from Oregon fans.

"It's been a great career. It's been a lot of ups and downs," Nix said. "There's been some great adversity, too, that I've been able to learn from, and I wouldn't be here without.

"Every year, every step has been another journey, and I wouldn't have traded anything," he added.

--By Jose M. Romero, Field Level Media