Justin Timberlake and Jay-Z are set to perform together at the Wireless festival.
The two Suit And Tie stars, who are already billed to headline on separate nights, will give their British fans a taste of their Legends Of The Summer US stadium tour when they take to the stage for a joint show on July 14.
They will be joined by hip-hop pioneers A Tribe Called Quest in their first UK performance in 20 years, along with rapper A$AP Rocky, Nas and Rizzle Kicks.
Justin - whose new album The 20/20 Experience is being streamed on iTunes until its release on March 18 - is already confirmed to headline the opening night of the three-day festival on July 12. Snoop Dogg (now known as Snoop Lion), John Legend, Trey Songz, Frank Ocean, Wretch 32 and Conor Maynard are among the acts also performing on the day.
Jay-Z, whose real name is Shawn Carter, will play on July 13, alongside Brit winner Emeli Sande, Rita Ora, Kendrick Lamar, DJ Fresh and Calvin Harris, Thriftshop singers Macklemore and Ryan Lewis.
This year's Wireless festival will take place at the Queen Elizabeth Olympic Park in east London rather than Hyde Park as in previous years.
Dennis Hone, chief executive of London Legacy Development Corporation, said: "It's a credit to Queen Elizabeth Olympic Park that this year's Yahoo! Wireless Festival is the fastest selling in the event's history and we are delighted that both Justin Timberlake and Jay-Z will be performing a third date here in July with a preview of their Legends of the Summer Tour."
Tickets for the final date will be available from 9am on March 15 from www.wirelessfestival.co.uk.