Nathan Lyon has declared he is in the best shape of his career ahead of his 39th birthday, having given up alcohol and taken up an intense fitness regime.
Australia's bowlers again showed off their longevity in Durban on day three, working over South Africa to dismiss them for 284 and set up a 106-run first-innings lead.
As a quartet, Lyon, Pat Cummins, Mitchell Starc and Josh Hazlewood also became the first in history to take 600 wickets in Tests played together on day three.
For Lyon, that mark is extra sweet ahead of his 39th birthday next month.
The past year has been the most difficult of the spinner's career, forced to overcome a serious hamstring tear and twice being overlooked for Test matches.
But he has also made clear he wants to play on until at least the end of next year's Ashes, which will make him Australia's oldest frontline bowler since Bill O'Reilly in 1948.
Beyond that, Lyon won't set an end date.
The fingerspinner has given up alcohol for the past nine months, and has also spoken previously about increasing bike riding and fitness work to get back.
And for that reason, Australia's second-leading wicket-taker insists he never doubted he would be back on the big stage.
"I'm probably in the best shape of my career," Lyon said, after taking 2-58 in Durban on Sunday.
"The amount of work that I've put in, I've never had any doubt that I'll get back.
"I haven't had any alcohol for a fair while now, but I'm just trying to squeeze as much out of the lemon as possible that I can.
"I still feel like there's a lot of decent cricket ahead of me, that's for sure."
Australia's experience did show with the ball on day three at Kingsmead, before Nic Maddinson's unbeaten 17 helped the tourists to 0-33 at stumps and a lead of 139.
The Proteas came out hard, with Aiden Markram and David Bedingham adding 60 runs from the first 10 overs of the day with a flurry of drives.
But Australia's quicks pulled back their lengths slightly and tightened the screws, as South Africa lost 3-15 in 10 overs and lost any control of the day's play.
That was in part helped by Steve Smith's brilliant fielding, who moved early in anticipation and had both Temba Bavuma and Kyle Verreynne caught reverse-sweeping at slip off Lyon.
Lyon, Cummins, Starc and Hazlewood had already entered this Test as the first in history to each have 300 wickets to their name going into a match.
And they now have a combined 600 in Tests played together, with the next highest being Moeen Ali, James Anderson, Stuart Broad and Ben Stokes for England with 415.
"That's pretty bloody special moment if you ask me," Lyon said.
"They're things that I'll look back at when my career is done and look at that and go, that's pretty cool."