Saturday's stunning against-the-odds victory over Sydney was the best in his club's short history, Gold Coast defender Rory Thompson says.

Thompson, who was on the Suns' inaugural AFL list in 2011, kept Swans superstar Lance Franklin goalless as his side recorded the upset of the season at the SCG.

"Best win we've ever had, hands down," a beaming Thompson said after the game.

"It was a great effort from everyone, all the young boys stood up. It was amazing."

Gold Coast trailed by 29 points at quarter-time, and at that stage, it was looking like yet another long afternoon for the club, but the young visitors wrote their own script after that to claim a 24-point victory.

Thompson, 27, said the club's previous best effort – a 26-point win over Fremantle in Perth in round two, 2016 – had been "topped by a mile".

"I don't think anyone gave us a chance today, and I'm just stoked," he said. 

"I know internally – we've been playing well in patches – we had the belief there.

"We knew if we could put four quarters together we could challenge anyone, and we didn't quite get four quarters, we got three. But that was enough."

Franklin was well held on Saturday and finished with 0.3. Two of those behinds came from long-range early in the final term as the surging Swans mounted a challenge. 

However, Thompson had Buddy's measure and was rarely beaten when caught one-on-one with the four-time Coleman medallist.

"I have to give all credit to everyone up the ground, because the way it was coming in was giving me every chance to do my job," Thompson said.

"That made my day a lot easier. He's still a great player and hard to stop."

Lachie Weller (23 possessions, two goals), Jarrod Witts (56 hit-outs), Will Brodie (28 touches), Touk Miller (25 touches) and Steven May (23 touches, 14 marks) all stood up for the visitors.

The Suns were in front by 20 points at three-quarter time and showed maturity in the final term when Sydney booted the first two goals.

"That's definitely been something we've been trying to work on," Thompson said.

"In the past couple of months if we concede a couple that turns into three, four, five, six.

"We just said at three-quarter time, if they kick the first or we kick the first it's nothing different. We just stick to the game-plan and what's been working.

"It was great maturity from the young boys to be able to do that."