Video: Mike Tyson Posts Clip of Boxing Lesson with 'GOAT' Serena Williams

Boxing legend Mike Tyson tweeted video Wednesday night of a training session with tennis superstar Serena Williams:

Tyson referred to Williams as the "GOAT," or greatest of all time, and suggested he wouldn't want to be on the receiving end of her punches.

The 38-year-old Williams is still looking to tie Margaret Court's all-time record of 24 Grand Slam singles titles after reaching the finals of both Wimbledon and the U.S. Open the past two years and falling short all four times.

While Williams is perhaps the greatest women's tennis player of all time, Tyson was one of the most remarkable boxers of his era as well.

The 53-year-old Tyson is a former unified heavyweight champion who began his professional career 37-0 before a shocking loss to Buster Douglas in 1990. Of Tyson's 50 career wins, 44 were by way of knockout, making him one of the most dangerous and powerful punchers in the history of the sport.

Serena, also known for her prodigious power on the court, has continued to go deep in majors at an age when most have long since retired.