The first golfers to break the £1million payout barrier are Justin Rose (25/1) and Lee Westwood (14/1) – Rose has been the subject of a £15k each-way shop bet.
Donald and McIlroy, both 20′s, will trigger £500k payouts as punters look to players who can handle the European conditions.
Alex Donohue of Ladbrokes said: “We set out to get the big boys in the book and have done just that. Rose & Westwood can do some serious damage at this stage.”
He added: “Woods is in unfamiliar price territory. His backers haven’t had the chance to get double figures for their money for an age.”Ladbrokes latest betting The Open winner
Tiger Woods 10/1
Lee Westwood 14/1
Luke Donald 20/1
Padraig Harrington 20/1
Rory McIlroy 20/1
Justin Rose 25/1
Graeme McDowell 33/1
Phil Mickelson 33/1