I guess it sounds strange for me to nominate my best round ever as being in an event that I didn't actually WIN.

Without a doubt due to horrible conditions my 1st round at The 1993 Victorian Open Championship at Woodlands Golf Club near where I grew up was my finest professional round ever.
I shot an 8 under par 64 on that day in torrential rain and sideways wind in the afternoon when the conditions were even worse than for the morning play.
I believe the second best score that day was a 70 by Mike Harwood in the morning play. So I was the only person to shoot in the 60's that day and had the day's best score by 6 strokes !!
Unfortunately I didn't win the event and finished runner-up to Lucas Parsons but it was still a week to remember.

Raising my hands in disbelief at the way things are going for me during my play at the 1993 Victorian Open Championship Question/Answer interview with golfer course designer and writer Mike Clayton about the best round of golf he had whitnessed during his career

 

Mike Clayton interview discussing my first round as one of the most unbelievable rounds he had witnessed throughout his career.