J.W. Walsh powered the explosive Oklahoma State offense past Texas-San Antonio for a 56-35 victory at the Alamodome.
Walsh threw for 326 yards and four touchdowns while adding another score on the ground. The sophomore was named the starting quarterback after taking over for senior Clint Chelf in last week's 21-3 win over Mississippi State.
"We had a lot of things going for us," Walsh said. "When you run that up-tempo stuff and the defense is having a hard time keeping up with you, then a lot of things are going to work for you."
Josh Stewart led the Cowboys' (2-0) receiving corps with five receptions for 97 yards for a touchdown.
Missed opportunities in the first half hurt the Roadrunners (1-1), who would fall behind by 35 points before scoring four fourth-quarter touchdowns. Eric Soza completed 24-of-41 passes for 308 yards with three touchdown passes and two interceptions.
Texas-San Antonio's defense did not force any turnovers, while allowing a total of 605 yards.
"The thing I told our players is we have to build on this," UTSA head coach Larry Coker said. "If we build on the positives we can be a good football team."
Oklahoma State struck first on its opening touch with a 65-yard drive down the field that was capped off by a 10-yard touchdown pass from Walsh to Jhajuan Seales.
The Roadrunners answered back on the very next drive with a Kenny Bias run from six yards out to even the score.
Following a 22-yard reception from Tracy Moore on Oklahoma State's ensuing possession, Brandon Sheperd hauled in a 19-yard pass from Walsh to put the Cowboys back on top.
Shaun Lewis picked off Soza on the first play of Texas-San Antonio's next drive, but the Roadrunners stopped the Cowboys from gaining a yard to force a punt.
Following another UTSA punt, Walsh completed all six of his passes on a 7- play, 63-yard scoring march that culminated in a 10-yard TD grab by Stewart.
The Roadrunners put together a 61-yard drive on their ensuing touch, but Sean Ianno missed a 31-yard field goal.
Oklahoma State took advantage of the missed opportunity on its next possession, as Walsh hooked up with Stewart for 56 yards before punching it in from four yards out to make it 28-7 with less than five minutes left in the half.
Ryan Simmons picked off Soza on UTSA's next touch and after Walsh hit David Glidden for 29 yards, Jeremy Smith scored from one yard out to extend the margin to 35-7.
After Walsh and Blake Jackson combined for an early third quarter touchdown, Chelf took over at quarterback for the Cowboys.
UTSA outscored Oklahoma State in the second half, scoring a pair of touchdowns in a 1-minute, 55-second span early in the fourth. The first score came on Cole Hubble's 10-yard TD catch that capped a 92-yard scoring march.
After halting the Oklahoma State offense on the next drive, Kenny Harrison returned a Kip Smith punt 62 yards to set up a quick 19-yard touchdown pass from Souza to Bias.
Chelf completed a 44-yard pass to Seales before adding another touchdown with a 33-yard scoring strike to Charlie Moore to give the Cowboys a 49-21 lead.
Bias scored his third touchdown of the day on a 67-yard heave from Souza.
Desmond Roland finished off a 72-yard drive with a 21-yard TD catch before Tucker Carter took over under center for the Roadrunners' final drive.
Carter led his squad down the field before finding Aaron Grubb for a 15-yard touchdown to cap an 11-play, 81-yard trek and account for the final margin.
This is the first meeting in history between these two teams ... Oklahoma State became the first ranked team to ever play at the Alamodome ... Texas-San Antonio managed 135 yards on the ground ... The Cowboys scored on five of their six first half possessions.