Wales' autumn clash with New Zealand has sold out the 74,500-capacity Millennium Stadium and tickets for the visit of World Champions South Africa are on course to follow suit.
Tickets for the game sold out within hours of the Welsh Rugby Union placing them on general sale.
"We expected demand to be high for the All Blacks game, but to sell-out in the space of an hour is impressive and fans should now act quickly if they want to watch Warren's side face the World Champions, Australia and Canada, because there has been no let-up in ticket enquiries," said WRU group chief executive Roger Lewis.
"The feel-good factor in Welsh rugby after the Grand Slam shows no sign of dying down and Wales's impressive showing against the Springboks in the second Test on tour this summer has obviously whetted many an appetite.
"For us to take our tickets out to the market place this early in a season, over three months before our Autumn fixtures take place, is a first for the WRU."
The 2017 RBS 6 Nations was watched by record numbers of fans
29 March 2017, 12:25pm
After an enthralling RBS 6 Nations Championship of twists, turns, and no small amount of drama on the last day, figures show the RBS 6 Nations is going from strength to strength, year on year, with no sign of slowing down.