Heineken Cup Final worth £24m to economy in Wales
The Heineken Cup final is the most economically lucrative single day major event Wales has hosted, says the Welsh government.
Research following European rugby's 2011 final showed 83,000 fans attended the Millennium Stadium clash, boosting the local economy by £24m.
Around 70,000 fans are expected at Saturday's final, which will see London-based Saracens take on Toulon.
Cardiff hosts the event for a record seventh time this year.
The Welsh government said research after the 2011 final showed 70,000 of the 83,000-strong crowd came from outside Wales.
And of those more than 42,000 stayed overnight, with many staying two or more nights and putting money in the tills of hotels and other businesses.
Economy Minister Edwina Hart said the high profile event gives important media exposure to Wales as well as "economic spin-offs".
This year's match will be the last game played on a grass surface after the Welsh Rugby Union agreed to install a new hybrid pitch at the Millennium Stadium this summer.
A number of city centre road closures will be in place on Saturday between 15:00-20:00 BST.
On Friday afternoon there was 32 miles of start-stop traffic on the M4 heading to Cardiff as rugby fans joined the bank holiday queues ahead of the Amlin Challenge Cup at Cardiff Arms Park.
Northampton Saints later gained their second success in the competition with a 30 -16 victory over Bath.