The first time PJ Tessmann showed up face-painted in enemy territory to support his beloved Georgia football team, the Bulldogs lost, thus granting his high school buddy all the bragging rights he wanted.

Tessmann’s not about to make that mistake again.

Nearly 20 years ago, Alabama edged Georgia 29-28 in Tuscaloosa to Tessmann’s dismay — he was woofing during the game but sulking after it — but delighting Crimson Tide graduate assistant Dabo Swinney.

So now that No. 5 Georgia’s prepping for a primetime showdown at No. 8 Clemson a week from Saturday, the red and black facepaint won’t be necessary.

“I am a big Georgia fan, but now … I’ll be pulling for Clemson (Aug. 31),” Tessmann told The Post and Courier in a phone interview. “I bought my orange coach’s shirt all ready to wear. I’m all in for Clemson.”

Swinney has long sung the praises of the Clemson-Georgia rivalry, because he remembers watching the great clashes in the early 1980s as a kid rooting for Alabama.

“My best friend growing up was a Georgia fan, so I’ve kept up with the Bulldogs a long time,” Swinney said. “Clemson-Georgia’s special. Been hearing about it for a long time. It’s a great rivalry, and it’ll be a game for the ages, opening at night, everybody’s excited for college football.”

Tessmann moved to Birmingham the end of his sophomore year in high school from Marietta, Ga., a northwest suburb of Atlanta. The soccer standout enrolled at Pelham (Ala.), and earned a soccer scholarship to South Alabama, but he held strong to his Georgia fanship instead of picking a side in the Auburn-Alabama rivalry.

Even though Swinney had little interest in soccer, the football and basketball teammates were fast friends. After they graduated from Pelham in 1988, Tessmann would join Swinney — an Alabama football walk-on — in Tuscaloosa to live and train together during a few summers during their college years.

Tessmann and his wife, Kelly, are good friends with Dabo and Kathleen Swinney. Their families spent two weeks this past summer together at the Swinney beach house on Gasparilla Island in Boca Grande, Fla., and try to see each other for one Clemson home game and Christmas each year.

Today, Tessmann’s children — daughter Ashley, 13, and son Tanner, 11, both big into soccer — are in the same age range as the three Swinney boys.

That’s not all the Tessmann kids have in common with Will, Drew and Clay Swinney.

“They’re huge Clemson fans,” said PJ Tessmann, now an accountant controller in Birmingham. “They don’t know anything about Georgia. They’re all in with their Clemson gear; they don’t even have any Georgia stuff.”

But Tessmann’s not giving up on his Bulldogs — with the exception of one night in Death Valley. It wouldn’t do right by the shrine in his house — a “typical, over-the-top Georgia room” with pictures and a 10-foot blowup Bulldog displayed during the holidays.

“So this will be the first game,” Tessmann admitted, “I won’t be pulling for them.”

As for Swinney’s perspective, he’d like to remove the bitter taste from the last time Clemson faced Georgia — an embarrassing 30-0 home loss to open the 2003 season, in Swinney’s debut as the Tigers’ wide receivers coach.

“It was my very first game when I came here. I’ve got bad memories from that game,” Swinney said. “I’m not trying to really relive those.”

Eight days away, he’ll be backed by 80,000-plus fans in the stands — including a longtime pal.

“It’s been unbelievable to watch how he handles himself,” Tessmann said. “Knowing him as a friend in high school to where he’s gotten to now, it’s not necessarily surprising. It’s just great to see him get the opportunity, and I knew he would definitely prosper in that role.”