The goal that cost bookie William Hill £570,000

A Maltese villager who landed an amazing 683,783/1 punt on the football was the bane of the UK's biggest bookmaker as William Hill bemoaned a nightmare November for betting margins.

Accumulator betting on large numbers of football fixtures – where all the selections need to win to land the cash – is usually a mug's game as at least one match fails to follow the form book. But the 41-year-old waiter placed a successful one-euro bet on 19 fixtures landing £570,000 after Glen Johnson's late winner for Liverpool against Chelsea on 20 November secured the final leg.

Hills blamed the result for a fall in win margins from 19 per cent to 17 per cent over the fourth quarter as a host of favourites across, including Arsenal, West Ham and Charlton, all won. The losses added up one of the worst months for the firm in more than a decade although it clawed some cash back in a run of shock results over Christmas, including relegation struggler Blackburn's away win over champions Manchester United.

Ralph Topping, chief executive, said: "November was certainly a very good month for our football clients betting on small-stake, high-return multiple bets."

Despite the blow, the firm expects operating profits for 2011 to be in line with forecasts at about £274m. This is slightly down on 2010, when the bookmaker was boosted by a World Cup gambling frenzy.