Wales, resurgent and fresh from victory in Argentina, will find out just how much they have improved when they take on the world champions, South Africa, in their new home at the Millennium Stadium.
But whether or not Graham Henry's men can make it six wins in a row will not be the biggest talking point for the 27,500 who finally make it into the newly constructed 72,500 capacity Millennium Stadium. The "homecoming" international - Wales have played six home matches at Wembley in the past two years - will give the people of Wales, and those around the world who intend to pitch up for the World Cup, the first chance to see how the old Arms Park has been transformed into what Glanmor Griffiths, chairman of the Welsh Rugby Union and the Millennium Stadium plc, believes is "the finest rugby stadium in the world".
Well he would say that wouldn't he? And perhaps now is the time to start believing the words of chairman Griffiths. For two years he has been telling everyone that the pounds 126m stadium would be completed in time. Nobody believed him and even some of the World Cup directors had their doubts.
Yet on Saturday, bang on schedule, the opening game will kick-off at 5pm. Two more matches, with increasing attendances, will follow in August against Canada and France before the opening game of the World Cup on 1 October, when Wales face the Pumas again.
These are exciting times for Welsh rugby, and there is a feeling that something special might be on the horizon. Just how special will be put into clear perspective by the Springboks, who may well be missing half- a-dozen key men but will none the less present an acid test. After that historic 2-0 series win in Argentina the Welsh will be chasing a sixth successive win. Confidence is mounting, injuries have been falling and anything could be possible with a few more wins.
Even the Springboks, who a year ago humiliated the pre-Henry Welsh 96- 13 in South Africa, are wary of what might befall them on opening night at the Millennium Stadium.
"This time last year we were beating them 96-13, yet here they are having won five successive Test matches," Gary Teichman, the Springbok captain, said. "A lot has been spoken about the defeat last summer, but you can't really compare that with anything because they had so many players out of action through injury.
"However, they ran us close early last season at Wembley and could have beaten us had our boys not shown such great spirit in the final few minutes. People said that we were jaded and started making all sorts of excuses for us. If you remember we never made any excuses about tiredness or having played too many games in such a short space of time.
"We were certainly not suffering, it was just that Wales caught us cold and played a style of rugby that we didn't expect. All credit to Graham Henry, he has done a great job, and we are aware that the Welsh are getting better and better. They have beaten France, England and Italy and have just won twice in Argentina - that's not a bad record to go in to a game against us with."
Nor is the South Africans', of course - 18 wins in 19 matches, culminating in yesterday's little jaunt - a 101-0 win against Italy in Durban.
The Millennium Stadium, even without its final few adornments, is bound to take centre stage on Saturday but the new home of Welsh rugby, and so much more, could even be upstaged by Henry's men if they can make it six in a row.