"I remember we'd been going through a bit of a drought against the Wallabies and they'd put nearly a hundred points on us in two tests the previous summer, but that day we actually led midway through the second half and ran them pretty close," said Thomas.
"The try was an interception from a George Gregan pass and I just ran and ran. I was told at the time it was the longest try in international rugby, a 147 metre wonder try, all I know is I didn't celebrate much because I was too tired after running so far!"
Yet Alfie wasn't the only current squad member who was there on same day Aussie wing legend David Campese bowed out of international rugby.
Colin Charvis came on as a replacement for Hemi Taylor in the game and current National Kicking Coach Neil Jenkins remembers he had taken over at fullback from Wayne Proctor by the time the current Wales talisman went over for the longest of his record 37 tries.
"I remember seeing him running away from me and Joe Roff, I think, was after him. We thought he was going to catch him, but should have had more faith," he said.
Thomas was running away from Jenkins and Roff, but running towards current Wales scrum half Gareth Cooper, who was in the crowd as a fan.
"I was only 17 then, but I remember it really well," said Cooper. "Alfie was one of my heroes, he had long curtains for hair which was flapping around everywhere and he just seemed to fly for the line.
"I was playing for Pencoed Youth at the time and just dreaming of playing for Wales, we all had tickets in the old East End of the Arms Park and it was a really memorable day."
Gavin Thomas's contribution was more of a forwards effort during a game in 2001 when Wales went down 21-13 at the Millennium Stadium.
The replacement flanker scored the only try of the game after an inside pass from Rob Howley at the foot of a ruck just a couple of metres out and into injury time. That game was the first time Wales prevented Australia from crossing the line since 1975, 26 years and 12 games ago.
"Howley popped me the ball and I went over from a short way out," said Thomas. "Its always special to score for your country, it wasn't a particularly memorable one but I'd be quite happy to score a couple of un-memorable tries this weekend if it means we win the game."
Captain Thomas, the top try scorer in Welsh rugby, though he is still 17 behind Campese's record for the Wallabies, will be quite happy to score any way he can this weekend too, but he will make one piece of history regardless when he leads Wales out on Saturday as the country's most capped man (93).