Then it was in the all white strip of Swansea having just returned to Wales from Bristol. On that day he kicked-off his European campaign with four conversions in a 63-38 home win over London Irish.
Fast forward 13 years and the 35-year-old Thomas believes the British & Irish Cup could have a similar impact on the rugby landscape as the European tournaments did after the game turned professional.
"I can sense similar levels of excitement and apprehension within the Neath club now as there were back in the nineties at Swansea. There is a feeling we are about to step into the unknown," said Thomas.
"There is no doubt the Heineken Cup and European Challenge Cup completely changed the face of the professional club game in the UK and Ireland and perhaps the British & Irish Cup could have a similar impact at our level.
"It has certainly created a new buzz among the players and we are all looking forward to testing ourselves against one of England's top sides. We played Bristol in a pre-season friendly at The Gnoll a few seasons ago and it was a great night - especially as we won.
"For many of our players it will be a step up in quality from what they are used to in the Principality Premiership, but that can only be a good thing. We've got some very good youngsters in our squad and for the likes of hooker Gerwyn Price, centre Luke Ford, wing Dai Evans and prop Nicky Downes, this competition could be the making of them."
As well as Thomas, Neath also have 2005 Welsh Grand Slam full back Kevin Morgan and ex-Dragons and Scarlets centre Nathan Brew as internationals in their ranks.
But, as Thomas, concedes, it is not about them reliving past glories. The British & Irish Cup is all about increasing the standard and pushing the younger, more ambitious players.
"We like to think we are one of the most professional clubs in Wales at our level. We train an extra night each week, do gym work and prepare as well as we possibly can," said Thomas.
"But we really don't know what to expect from the likes of Munster or Heriot's FP in our Pool. We know all the English sides will be very strong and that is our only concern - will we be able to compete at this level.
"I know from my days at Bristol just how strong the English league system is, although those days were so long ago that Bristol were still wearing letters. But we're ready for the challenge and the pl