Last week’s kitty remained unclaimed until Friday, when Camelot urged players to check their tickets.
Just one sheet matched the winning numbers in the draw for 28 July, which were 5, 9, 29, 31 and 41, with the Lucky Stars 2 and 4.
The winner, who has not been identified, pockets a cold £51,702,049 – putting them in the same resources joint as Real Madrid brazen Bale, who is worth £54m according to the Sunday Times Rich List, and cocktail megastar Ed Sheeran, whose happening is estimated at £52m.
It continues a abounding capillary of fitness for British gamblers, being the fourth UK sheet to hit the EuroMillions kitty this year.
In Jun another player won £87m, while in Feb two ticket-holders separate a esteem worth scarcely £40m.
The week after that a UK leader collected £14m.
One of Europe’s biggest ever prizes went to Chris and Colin Weir in Ayrshire, who scooped £161m in 2011.
National Lottery organiser Camelot says tens of millions of pounds go unclaimed any year due to lost tickets bought in shops.
It pronounced the kitty will be paid out once the sheet has been certified and the leader will then confirm either or not to go public.
Andy Carter, comparison winners’ confidant at The National Lottery, said: “We’re gay the ticketholder has come brazen to explain their prize.
“This year is proof very propitious for UK players.”