The contest came down to an overtime finish after Ryan Sieg ran out of fuel late in the piece, with van Gisbergen called to pit lane to top up the #97 Chevrolet under that final Caution, while the top group stayed out.
He took the restart in seventh and went to the outside, with Kaulig Racing team-mate AJ Allmendinger on his inside in Car #16, before they went in opposite directions in the final laps.
As cars ahead ran out of fuel, van Gisbergen was third by the back stretch, where he stayed.
The podium in Race 2 of the season, after a 12th at Daytona, moves the three-time Supercars champion up to ninth in the Xfinity Series standings.
“It was pretty wild, not knowing what was happening,” he said.
“But, I knew we would be good having topped off.
“And then yeah, I tried to follow the cars through that I knew had fuel as well.
“To come home with a P3, a straight car, no damage, is an awesome feeling.
“I learnt so much this race, completing every lap. Really cool.
“I didn’t have any expectations, you can’t have them when you’re at a new place.
“I just came in, eyes wide open, and tried to settle in at the start.
“I guess the big thing is, I don’t know who anyone is yet.
“I come up behind someone and I don’t know what number [they are] or how good they’re going to be.
“I probably need to learn more cars so I can trust who to follow.
“But yeah, once I knew I was behind a good car I could commit a lot better.
“Every track is good at the moment. I just want to be racing, learning, and getting better every week.”
Having qualified 13th, without any practice running at Atlanta van Gisbergen finished 11th in Stage 1 and 17th in Stage 2, but dropped towards the back of the top 30 during the third and final stage.
Car #97 was hovering just outside the top 10 before the Sieg Caution which set up the dash to the finish.
Austin Hill won for the second weekend in a row in a Richard Childress Racing Chevrolet, with Chandler Smith second in a Joe Gibbs Racing Toyota.
The 2024 Xfinity Series continues next weekend at Las Vegas Motor Speedway.