Honorable mention: Tom Watson
Tom Watson was one of the world’s most dominant golfers in the 1970’s and 80’s, and is now estimated to be worth about $25 million. His career is notable for its longevity; he continued to play professionally until the age of 60. He did not achieve the “Grand Slam”, but he did win eight major championships.
Watson went on to compete in the Seniors, where he won six Senior major championships. He has also authored and co-authored multiple books on the sport of golf.