US Open champion Geoff Ogilvy is the best backed player in the field to win the Masters, according to William Hill.
The bookmaker has halved his price from 50/1 to 25/1 following a number of bets including a £2,000 each-way wager at 50/1.
Tiger Woods is 11/8 favourite to win his 13th Major and a 20/1 shot to win all four of the Major tournaments in 2007. Hill's also offer 7/4 that he wins one, 15/8 two, 11/4 none and 6/1 three.
The European challenge is said to be spear-headed by Henrik Stenson and Sergio Garcia who are 6/1 joint favourites to be top European finisher, with Masters specialist Jose Maria Olazabal offered at 8/1 and Colin Montgomerie a 28/1 outsider.
"The Masters is the biggest golf betting event after the Open and so far turnover is up on last year, we would expect the industry to turn over £20 million over the tournament," said Hill's spokesman Rupert Adams.
William Hill Top European: 6/1 Stenson, 6/1 Garcia, 13/2 Harrington, 8/1 Olazabal, 8/1 Donald, 8/1 Casey, 16/1 Rose, 20/1 Langer, 20/1 Jimenez, 20/1 Howell, 25/1 Poulter, 25/1 Fasth, 28/1 Montgomerie, 28/1 Clarke, 28/1 Bjorn, 33/1 Westwood, 33/1 Pettersson, 40/1 Karlsson, 40/1 Edfors, 50/1 Dredge, 80/1 Ferrie, 100/1 Woosnam, 100/1 Faldo, 125/1 Ramsay, 125/1 Guerrier, 150/1 Lyle, 300/1 Ballesteros.