The Millennium Stadium has sold 20,000 tickets, and counting, for the event which will also see Wrexham stuntman Jason Rennie attempt a World indoor distance record for a motorbike jump.
That attendance figure is on a par with the biggest Supercross events throughout the rest of Europe, with events at the Bercy indoor arena in Paris and Palexpo Stadium in Geneva attracting similar crowds.
The sport regularly out sells Grid-iron in America with 70,000 crowds entertained at the LA Coliseum, but the Millennium Stadium will still match other indoor venues in the USA like the MGM Grand Casino in Las Vegas which has a 20,000 capacity.
Other venues in the UK - the Sheffield Arena, the NEC in Birmingham and Earl's Court - attract 8,000 strong crowds, but promoters hope that un-precedented enthusiasm for the event in Wales will help to grow the sport in the UK to the grandiose proportions it enjoys across the Atlantic.
"We are already negotiating with the Millennium Stadium to bring further Supercross events to Cardiff as a direct consequence of the overwhelming response we have had so far," said owner of Future West International, John Hellam, who is running the event.
"There has been a strong take up throughout Wales and it must be the Millennium Stadium factor that has got people excited.
"It's great news for the future of Supercross in Wales because I can guarantee that everyone who turns up this time will be back for more when we return, and they will be wanting to bring their friends to share in the spectacular experience.
"The capacity at the Millennium Stadium for our event will be 50,000 and there is no reason why we can't be reaching that kind of target in years to come - the event really is that good."
The Supercross track at the Millennium Stadium was constructed within a 60 hour time limit, with the first pallet of grass removed on the final whistle of Wales' Euro 2004 qualifier against Russia.