But the Cowboys defense, directed by first-year coordinator Glenn Spencer, also deserves much of the credit, shutting out Mississippi State after allowing a 57-yard drive and the Bulldogs only points of the game on the first possession of the game.
The three points is the fewest the Cowboys have allowed a team from a major BCS conference since shutting out Bedlam rival Oklahoma, 12-0, in 1995.
"I haven't talked to (offensive coordinator) Mike (Yurcich) but I can't imagine that J.W. isn't going to be the starter in the next game," said OSU head coach Mike Gundy. "I say that with all respect in the world for Clint. It didn't go well for him today.
"J.W. came in and played very well, and provided a spark for us. We need Clint. Clint's a big part of this team. There could be a time we need him again; we've been down that road. I just don't think there's any reason to think that we wouldn't want J.W. to start the next game, so we'll have that conversation with him.
"But this was a great team effort. The attitude and the preparation of everybody involved was really good," Gundy said.
The Cowboys only had three first downs when Walsh trotted out to lead the offense late in the first half. The defense forced Mississippi State's fourth punt of the first half to give the offense the ball on the 31-yard line.
Running back Desmond Roland picked up nine rushing yards on the first two plays and then Walsh made one of the game's biggest plays on a third-and-1 from the 40. Walsh kept the ball, turned the corner around the left end and wasn't run down until he'd raced 46 yards down the sideline to the Bulldogs' 14.
Three plays later, Walsh called the same play and was untouched while scoring on a 3-yard run as the Cowboys took a 7-3 lead with 2:16 remaining in the first half.
Walsh and the Cowboys took control of the game after receiving the opening kickoff of the second half. Walsh was 4-for-5 passing for 31 yards (the only incompletion being what appeared to be a 19-yard TD pass to Roland that was overturned by the replay official) and ran for 11 yards on his only carry in leading an 11-play, 75-yard that culminated with running back Jeremy Smith's 1-yard scoring run just four minutes into the second half.
OSU's third and final touchdown was also an impressive drive – going 82 yards in nine plays – with Smith and Roland doing much of the work. The two Cowboys combined for 56 rushing yards on the drive (Smith 41 yards on two carries and Roland 15 yards on three attempts), while Walsh was 2-of-3 passing for 11 yards. Smith's 20-yard touchdown run capped off the drive early in the fourth quarter.
The Cowboys running game was outstanding with both Walsh (125 yards) and Jeremy Smith (102 yards on 15 carries) surpassing the century mark. The team ran for 286 yards on 40 carries, an average of 7.2 yards per attempt.
Gundy had said last week that both Chelf and Walsh would play in the game, but it was not known who would start or how much either would play.
"No matter what the reps were or the situation is or who's starting you've always got to be prepared because you're always just one play away from playing," said Walsh. "The team really rallied around the whole situation. They knew how it was going to be. It worked out for the best."
Gundy said the situation favored the option game the Cowboys ran while Walsh was at quarterback.
"In order for us to be able to throw the football at Oklahoma State we have got to be able to run the ball. We were really struggling in that area (early in the game)," said Gundy. "We didn't have tempo, we didn't have rhythm, and for that reason we struggled.
"Then when J.W. came in after a couple of series we had a spark. The hand he was dealt played in his favor because the option game, the scheme that coach Yurcich brought with him that we had put in, worked to his advantage because Mississippi State hadn't seen it, and we were getting a guy open in the field running the football.
"In my opinion, they weren't really able to come up with an answer because we were able to do it out of several different sets. Once that happened it allowed us to open up and throw the ball a little more, and it allowed us to get into our base sets and rum some tempo and run the football. It kind of got us rolling a little bit, and the defense continued to play well."
Walsh's running ability gives the Cowboys a few more options at quarterback.
"We knew going into the game that was part of the game plan; that we were going to have those options to run," said Walsh. "We knew going into the game it was going to be a big hitter for us because they hadn't seen it on film. This was the first time we'd done it.
After knowing for weeks that that was part of the game plan, it was fun to see it actually unfold."
The Bulldogs' only points came on Devon Bell's 40-yard field goal after Mississippi State drove from its own 20 to the Cowboys 23. The Bulldogs drove 57 yards on 13 plays to take the early lead, but they had no answer for Walsh and the Cowboys.