And a day earlier Biarritz Olympique and Toulon will go head-to-head in the Amlin Challenge Cup final at the Twickenham Stoop (20.00) to get ERC's unique festival of European club rugby under way.
There are only a few hundred Heineken Cup final tickets remaining of the 55,000 tickets made available for public sale. Tickets are available from www.ticketmaster.co.uk/heinekencupfinal or call UK 0044 844 847 1530 or International 0044 208 616 5111.
Both clubs will receive an allocation of 7,500 tickets for their own supporters. Details of club distribution are now available on ercrugby.com
Fans can also buy a ticket for both finals and avail of a £10 discount on a £35 Amlin Challenge Cup final ticket; Amlin Challenge Cup final tickets start from £25, with a group offer of 4 for £80.
Meanwhile on the Twickenham pitch Leinster Rugby will be bidding to win an unprecedented three Heineken Cup titles in four years and become only the second club to win back-to-back titles. Leicester Tigers (2001 and 2002) are the only club so far to successfully defend their title.
For their part Ulster Rugby, the 1999 champions, will be bidding to become only the sixth club to win two or more titles in what will be the fifth one-nation final - but the first all-Irish final. There have been three all-French finals and one all-English final.
And the all-Irish final means Ireland will have an additional place in the 2012/13 tournament with Connacht Rugby joining Leinster Rugby, Munster Rugby and Ulster Rugby.