Tyler Allgeier ran for a career-high 218 yards and three touchdowns to help No. 13 BYU beat Utah State 34-20 on Friday night.

BYU (5-0) beat Utah State (3-2) for the second straight time in the Battle for the Old Wagon Wheel rivalry series.

Baylor Romney threw for 187 yards and a touchdown on 15-of-19 passing in the first half but was injured when his head hit the turf hard just before halftime. He sat out the second half. He made his second consecutive start with Jaren Hall sidelined because of a rib injury.

CLICK HERE FOR MORE SPORTS COVERAGE ON FOXNEWS.COM

"He obviously couldn’t come back and play the game," BYU coach Kalani Sitake said. "We had to protect him and keep him safe."

Third-string quarterback Jacob Conover led the offense after halftime. The freshman threw for 45 yards on 5-of-9 passing in his college debut.

It was the first football game Conover had played in 3 1/2 years.

"It was a moment I prepared for," Conover said. "When it came, I had a little bit of butterflies. It was my first collegiate game. But it had been a moment I had been preparing for, for a long time."

Logan Bonner threw for 276 yards and two touchdowns for the Aggies. Bonner left with eight minutes to go because of a knee injury.

The Aggies finished with 22 rushing yards — snapping a streak of 16 consecutive games with at least 100 rushing yards.

"It won the game for them," Utah State coach Blake Anderson said. "They controlled the line of scrimmage for the most part."

The Cougars scored on their first four drives and averaged 9.1 yards per play before halftime. Romney completed his first eight passes, and Allgeier nearly eclipsed 100 rushing yards before halftime.

The Cougars took a 7-0 lead after Allgeier took a hit and burst down the sideline for a 22-yard run. Malik Moore intercepted Bonner’s pass at the BYU 26 to set up the scoring drive. Allgeier broke free and raced 59 yards for his second scoring run in the second quarter, pushing the lead to 24-10.

Allgeier’s second touchdown helped BYU regain a little momentum after Justin McGriff hauled in a 21-yard reception to cap an 18-play, 75-yard drive for Utah State that took 7 1/2 minutes off the clock and cut the Cougars’ lead in half.

Bonner connected with Tompkins on a 28-yard strike to cut it to 27-20. The Cougars struck back when Allgeier raced 67 yards to set up his own 1-yard plunge two plays later, giving BYU a 34-20 lead with 8:40 left.

THE TAKEAWAY

Utah State: An inability to generate any running attack doomed the Aggies. Utah State totaled a season-low in rushing yards and averaged 0.6 yards per carry.

BYU: Romney’s injury before halftime took some wind out of the sails for BYU on offense. The Cougars were aggressive and moved the chains with ease in the first half. They became more conservative and punted on three straight drives in the third quarter before getting back on track behind Allgeier’s running.

WIRE TO WIRE

BYU has not trailed this season, although the Cougars have had all five opponents so far rally within a score at some point in the game before they’ve grinded out a victory.

Through five games, the Cougars are winning by an average margin of 9.8 points per game.

"We’re coming out hot and confident," BYU linebacker Ben Bywater said. "There’s pros and cons to both. You want to be in tough situations, so you can bounce back. But I’m proud of our guys. For us not to trail is something to hang our heads high about."

QB UPDATE

Hall missed his second consecutive game after injuring his ribs on BYU’s final drive against Arizona State. The redshirt sophomore practiced with the team during the week, but ultimately did not suit up for Friday’s game.

The Cougars are hoping to have Hall back when they play Boise State in eight days.

"Jaren’s close," Sitake said. "He practiced, but we just didn’t feel like he was good enough yet. And we felt like Baylor had a better week of practice. We’re just trying to feel it out and figure out what’s best for the player, number one, and then what’s right for our team."

QUOTABLE

"They were a little bit bigger and stronger than us today, but that will not last. We will recruit our tail off, we will develop our tail off, and we will make this a battle every stinking year. This is one we won’t forget." – USU coach Blake Anderson vowing to make the rivalry with BYU more competitive in future meetings.

POLL IMPLICATIONS

BYU could make a push toward a Top 10 ranking depending on what happens to the teams ahead of the Cougars on Saturday.

UP NEXT

Utah State: At UNLV on Oct. 16.

BYU: Hosts Boise State on Oct. 9.