Lowest score under par in a professional golf tournament (single round)

The lowest golf score below par in a single round of a professional golf tournament is -14 and was achieved by Richard Wallis (UK) who shot 59 at the PGA Southern Open Championship OOM Pro-Am on the Par 73 course at the Drift Golf Club, East Horsley, Surrey, United Kingdom on 2 June 2013. Richard Wallis shot 29 on the front 9 and 30 on the back 9, he managed 10 birdies and 2 eagles. While there have been lower scores recorded in a single golf round (58) they were on 71 par courses or less.