AUSTIN, Texas -- Backup quarterbacks Case McCoy and David Ash pumped new life into a struggling Texas offense and Cody Johnson scored a fourth-quarter touchdown as the No. 24 Longhorns rallied to beat BYU 17-16 Saturday night.
With the younger brother of former Texas QB Colt McCoy and Ash rotating snaps after ineffective starter Garrett Gilbert was pulled in the second quarter, the Longhorns (2-0) used a punishing running game to rally from a 13-3 halftime deficit.
McCoy took most of the snaps on the drive to the winning touchdown, twice hitting Jaxon Shipley for big gains before Johnson punched in his second touchdown.
Jake Heaps led BYU (1-1)with 235 yards passing with one touchdown and two interceptions.
Justin Sorensen kicked field goals of 30, 33 and 32 yards for BYU, which had rallied from a 13-0 deficit to beat Mississippi on the road in the first game.
Playing their first season as football independents, the Cougars had a good chance to grab a second straight road win over a team from one of the country's power conferences, but wilted badly as the game wore on.
The temperature was 98 degrees at kickoff and Texas' running game pounded out big yards behind the Longhorns young quarterbacks. D.J. Monroe had two big runs in Texas' first touchdown drive in the third quarter. Malcolm Brown led the Longhorns with 68 yards rushing.
The new QB duo may push Gilbert out of the starting role.
Gilbert won a four-way battle in training camp to keep the starting job after throwing 17 interceptions in Texas' 5-7 season in 2010. But he was just 2 of 8 for eight yards with two interceptions and was lustily booed by the home crowd before he was pulled.
After the second interception, Heaps drove BYU 97 yards on 13 plays for the only touchdown of the half, a 6-yard toss to Ross Apo for a 13-0 Cougars lead.
The McCoy-Ash rotation failed to pick up a first down on its first series. The Longhorns finally scored after Heaps threw an interception on the BYU 29 and Justin Tucker kicked a short field goal to make it 13-3 at haltime.
BYU held Texas to just 88 total yards and three first downs in the first half.
Texas stuck with the backup QBs to start the third quarter and scored on its first possession. The Longhorns drove 68 yards -- all on the ground -- to set up Johnson's 1-yard touchdown run that made it 13-10. Monroe provided the big play with a 29-yard run and the BYU defense, so stout up to that point, looked helpless against Texas' power and speed rushers.
The boos that rained down in the second quarter quickly turned into chants of "Texas Fight!"
BYU led 16-10 after Sorensen's third field goal, but the Cougars were clearly unsettled.
McCoy then led an 8-play scoring drive that started at the Texas 48, connecting twice with Shipley for big gains before Johnson scored on a 4-yard run up the middle that put Texas ahead for the first time with 8:46 to play.
The Longhorns put the game away with a trick play reverse pass from Shipley to David Ash that picked up a key third down with under 3 minutes to play.