Denmark's Thomas Bjorn and English amateur Tom Lewis share the lead after the opening round of the 140th Open Championship at Royal St George's.

On a day when patchy rain and stiff sea breezes allowed Royal St George's to bear its teeth at the 156-strong field, the 41-year-old Dane seized the lead early on with a five-under 65 that included seven birdies and that stood for most of a marathon day before Lewis made his move in the early evening.

One stroke back from that pair was 47-year-old Miguel Angel Jimenez of Spain; 2009 US Open champion Lucas Glover and fellow American Webb Simpson.

Tournament favourite Rory McIlroy, the newly-crowned US Open champion, ended a three-week break by bogeying two of his first three holes, only to steady the ship and fire a one-over 71.

Speaking after his round, the Hollywood player said: 'On a day like this, I know better than most people, you can shoot a high number and put yourself out of the golf tournament. So it was nice to go out and shoot a decent score.

'I said yesterday, if the conditions stayed the same I'd take two 70s over the first two days, and if I shoot 69 tomorrow with similar conditions, I'll be really happy going into the weekend.'

The top two ranking players in the world, English pair Luke Donald and Lee Westwood, also finished on one over, while top American hope Phil Mickelson, at 41, was just ahead of them at level par.

Darren Clarke and Graeme McDowell are well in contention after posting rounds of 68 to lie three adrift of the leader, while 2007 & 2008 champion Padraig Harrington fired a 73.