NEW ORLEANS — Hunter Renfrow was a little kid when his father, Tim, constructed a goal post out of PVC pipe and stationed it in the yard at the family house in Myrtle Beach, South Carolina.

“I envisioned making the game-winning kick for the national championship for Clemson,” Renfrow said.

Kicker seemed like the most realistic college football option for young Hunter, the son of a 5-foot-6 high school coach. He never figured to be big enough to play another position — especially at his dream school, Clemson.

Renfrow still isn’t big enough — his listed height (5-foot-11) and weight (180 pounds) both seem significantly exaggerated. His hands are notably small. Add in a receding hairline and this is guy who is so physically unremarkable that he could blend right in at a CPA convention.

But the former walk-on wide receiver has become the most improbable of all Alabama beaters over the last two seasons.

Hunter Renfrow got that Clemson national championship he envisioned as a kid, but did it with his hands and not his foot. He made the game-winning catch last January with one second left, the most dramatic ending imaginable to a college football classic.

It was Renfrow’s second touchdown of the game, and the last of his career-high 10 receptions. A year earlier, as a redshirt freshman, Renfrow came out of the woodwork to make seven catches (also a career high at the time) for 88 yards and two TDs against Alabama in the title game.

Clemson has produced a dazzling array of NFL receivers, dating back to Dwight Clark and more recently DeAndre Hopkins, Sammy Watkins, Martavis Bryant and Mike Williams. But none of them made the most famous catch in school history.

That honor belongs to itty bitty Hunter Renfrow, the one guy Nick Saban and Alabama’s mighty defense cannot seem to cover.

“Hunter Renfrow,” said Saban on Saturday, “is a pain in the you-know-what.”

Renfrow’s response: “Hopefully I’ll be a pain in the butt again Monday night.”

How it all happened is unlikely in the extreme. Renfrow grew up running the option in the front yard with his dad and siblings (he’s one of six children). He remained an option quarterback at Socastee High School in Myrtle Beach, playing for his father. If anything, his athletic future figured to be in baseball.

But football called to Renfrow, and so did the idea of playing at his mom’s alma mater and dream school, Clemson. He decided to walk on.

The fit of player and coach was fortuitous. Dabo Swinney himself was a walk-on wide receiver in his playing days, at Alabama. He would give the kid a chance, and the kid would do everything possible to give himself a chance.

Renfrow practiced catching tennis balls. He figured out that his vision was steadier running on the balls of his feet and not his heels. He mastered routes. He honed his small-space quickness. He knew the game.

After a redshirt year spent on the scout team, Renfrow worked his way far enough up the depth chart to get playing time right away. He had two catches in his first game, against Wofford, and three more the next week against Appalachian State. He scored a touchdown in his third game, at Louisville, and had a 24-yard reception the next game against Notre Dame.

Still, he was little more than an accessory part heading into the 2015 College Football Playoff. Renfrow surprised Oklahoma in the Orange Bowl semifinal with four catches for 59 yards and a touchdown. Then he shocked Alabama, making 21 percent of his career receptions to that point in a 45-40 loss to the Crimson Tide.

Last year his role expanded, but Renfrow still was just the fifth or sixth option in Clemson’s loaded receiving corps heading into the rematch with Alabama. Somehow, a defense littered with NFL talent couldn’t cover the little former walk-on.

By the time Clemson marched to the Alabama 2-yard line in the final seconds, Renfrow had become a prime target and several Tide defenders figured the play would come his way. Sure enough, “Crush,” as the play is called, had Renfrow lined up in the right slot. Walking to the line of scrimmage before the play, Renfrow had a vision in his mind of the grass on the Clemson practice fields. He briefly flashed back to spring practice — he said Crush was the first play the Tigers ran in spring ball, and now it would be the play that decided the national championship. Springing free off a controversial pick by teammate Artavis Scott, Renfrow was alone in the end zone corner. Deshaun Watson put the ball on the money, and there was no way Renfrow was going to drop the most important pass in Clemson history.

And this runt of a guy became an instant hero.

When Clemson came home, Renfrow returned to campus a sudden and somewhat reluctant celebrity.

“Signed a lot of Sports Illustrateds,” he said with a smile. “I’m sort of a shy guy. In kindergarten, I hated going to school and meeting people. I stayed under the table and cried, even during recess.”

There is no hiding now, not with Clemson-Alabama III coming up. Thanks to painful experience, Hunter Renfrow occupies a more prominent place on the Crimson Tide scouting report. He’s come a long way from the little kid dreaming of game-winning kicks for Clemson, and the journey isn’t over yet.

More from Yahoo Sports:
• Liberty Bowl stage collapses under celebrating Iowa State players
• Pete Thamel: USC falling to one of sport’s biggest disappointments
• New sports curse? Rival flag buried at Vegas stadium site
• Heisman winner Mayfield feeling sick ahead of Rose Bowl
• 49er is prepared to be blackballed by NFL teams