By Tony Jimenez HOYLAKE England (Reuters) - Former European number one Robert Karlsson set a sizzling early pace on a blisteringly hot day at the Royal Liverpool Golf Club by firing a three-under-par 69 in the 143rd British Open on Thursday. While the 6ft-5in (1.95m) Swede was inching his way to the top of the leaderboard alongside Spain's Sergio Garcia and American Rickie Fowler, who had both played eight holes, 14-times major champion Tiger Woods was treading water on the opening day. Woods, featuring in only his third competitive round after undergoing back surgery in March, dropped a stroke at the first hole after finding a greenside bunker with his approach. More...