The British and Irish Lions will play Argentina in Cardiff as a warm-up before next year's tour to New Zealand. A member of the Lions management told BBC Sport that the Welsh Rugby Union's bid to host the match at the Millennium Stadium has been accepted.
The WRU beat off a rival bid from Twickenham for the Pumas clash, which will take place on Monday, 23 May.
The Lions have never played Argentina on home soil before, but coach Sir Clive Woodward wanted a pre-tour match.
The last time the Lions played in Cardiff was in 1986, where they lost 15-7 to a Rest of the World XV in a match celebrating the International Rugby Board's centenary.
The Lions will leave for New Zealand soon after the game at the Millennium Stadium, with their first match on Kiwi soil on 4 June against Bay of Plenty.
With Woodward adamant that any player in the Lions squad can win a Test place, the game against the Pumas will be a full-blooded affair as players vie to impress the selectors.
The match is a huge boost to the cash-strapped WRU's finances, with an official announcement expected soon. Under chief executive David Moffett's cost-cutting measures, losses have been slashed from millions of pounds a year to just over �100,000 last year.
A full house for the Pumas match could earn the WRU �400,000, while the Millennium Stadium will also host this season's football FA Cup semi-finals and final.