Former Open champion Louis Oosthuizen set the pace on day one at Royal St George's on Thursday.

The South African, a winner in 2010, recorded a bogey-free six under par round of 64 in front of around 30,000 fans in Sandwich.

Oosthuizen is one shot clear of 2017 winner Jordan Spieth, whose 65 included four straight birdies on the front nine, and Brian Harman.

Fellow Americans Stewart Cink and Webb Simpson are among the players on four under while England's leading players are three shots off the leader.

Andy Sullivan, Danny Willett, Tommy Fleetwood, Jack Senior and Justin Rose all closed the day on three under, Senior and Rose not dropping any shots during their rounds.

Paul Casey sits tied 19th on two under, along with Dustin Johnson, Sergio Garcia and Francesco Molinari.

Brooks Koepka dropped a shot at the last to finish one under, while Richard Bland - who had the honour of being the first player to tee off - went round at level par.

A birdie at the last meant Rory McIlroy also carded a 70, a round that promised so much early on but quickly threatened to disintegrate as he dropped shots at five, six and seven. Two birdies in the last five holes means McIllroy starts day two six shots behind the leader.

Four birdies for the big-hitting Bryson DeChambeau were tempered by five bogeys as he went round in 71, a score matched by Lee Westwood and Darren Clarke - the last Open winner at Royal St George's in 2011.

Also at one over par was pre-tournament favourite Jon Rahm, who birdied the last.

It was a day to forget for Phil Mickelson, whose round of 80 included a double bogey at the last and left him 10 over par at the back of the field.

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