WACO, Texas -- TJ Finley threw for 298 yards with three touchdowns and ran for another score as Texas State stunned Baylor, 42-31, on Saturday night, with the Bobcats getting their first-ever win over a team from a Power Five conference in coach GJ Kinne's debut.

After going three-and-out on their opening possession, the Bobcat offense started to resemble the one Kinne assembled as coach at Incarnate Word last season. That team led all FCS teams with 51.5 points per game and was second with 581.2 total yards.

"That was pretty fun," Kinne said after the win.

The Bobcats had 448 total yards, and scored touchdowns on six of their next eight possessions after the initial drive. That included two first-quarter scores from Ismail Mahdi, on a 10-yard reception and 65-yard run, after they trailed for the only time at 3-0. They led 28-13 at halftime.

"I'm disappointed with our execution," Baylor coach Dave Aranda said. "There's a level of detail that it takes to execute, and a level of detail it takes to win, and unfortunately, we just did not have that tonight. I take full responsibility for that, and there's an opportunity now to address it, respond and own it, and get back to being better. And there's a lot of getting better to do."

Mahdi was the Bobcats' leading rusher with 83 yards on six carries, and Joey Hobert had six catches for a team-high 105 yards.

Blake Shapen threw for 304 yards and two touchdowns for Baylor, despite missing parts of the second half with an injury. After the loss, Aranda told reporters that Shapen injured his MCL, and will receive an MRI before his status is determined.

Mississippi State transfer Sawyer Robertson added 113 yards through the air in relief but was intercepted and fumbled on Baylor's final two possessions.

But Baylor, champion of the Big 12 just two seasons ago, struggled to find its footing on the ground in the loss. While the Bears finished with 417 yards through the air, they stumbled their way to just 108 on the ground.

"The inexperience -- and I don't want to use it as an excuse -- but there was some anxiety on that unit," Aranda said of the offensive line and the Bears' running game. "That's just college football, and you can't make it a thing. But for us, it was too much of a thing."

Baylor's offensive line was a little too jumpy early, with four false start penalties in the first quarter. The most damaging was the first, which was on first-and-goal from the 1 on Baylor's first drive, and it settled for a field goal. Baylor added two more on another promising drive at the Texas State 28 and 30 and again added a field goal, drawing boos from the home crowd.

"One of the biggest areas of improvement is that offensive line," Aranda said.

The road doesn't get easier for Baylor. Next Saturday, the Bears play host to No. 14 Utah (1-0), which is in its final Pac-12 season before joining the Big 12. The Utes defeated Florida, 24-11, on Thursday to open the season.

The Associated Press contributed to this report.