The South African golfer Louis Oosthuizen will tee off on the final day of the British Open at St Andrews with a four-shot lead over England's Paul Casey.
Oosthuizen shot a three under par 69 for 15 under overall while Casey's five under 67 was the equal best score of the day with Sweden's Henrik Stenson, who's four shots further back in a share of fourth with Spain's Alejandro Canizares and another Englishman, Lee Westwood.
Germany's Martin Kaymer is in outright third, seven shots behind Oosthuizen.
Overnight runner-up Mark Calcaveccia's plummeted down the leaderboard to 26th equal after a five-over 77.
Tiger Woods is in a share of 18th after a one-over 73. The American world number one is 12 shots off the pace.
