Fan vote: Serena Williams at her peak v Floyd 'money' Mayweather as a pro

Welcome to ESPN's fan vote, where you, the reader and sports fan, will decide which individual or team has been the most dominant in the 21st century.

For our third match-up, we have Serena Williams, arguably the greatest tennis player (male or female) of all time, up against one Floyd Mayweather, who went unbeaten his entire professional boxing career.

(Please vote in the poll at the bottom of this page to decide the winner.)

Peak Serena Williams (2013-2016)

Between February 2013 and September 2016, Serena Williams spent 186 consecutive weeks as the world's top-ranked singles player. Overall, only Steffi Graff and Martina Navratilova have spent more weeks than Serena Williams as World No. 1. However, Serena is ahead of them on the list of players with the most Grand Slam singles titles.

Serena won nine of the 19 majors she took part in during the above mentioned period, besides two runner-up finishes and two semifinal appearances. Her win-loss record in majors held during that period stands at an imposing 98-10, for a win percentage of 90.74.

Moreover, she also won 12 Premier Mandatory and Premier Five tournaments (the top tier of tournaments on the WTA tour) in that span and was runner-up in three other Premier Mandatory/Five tournaments. In fact, she reached the quarterfinals or better in 25 of the 27 Premier Mandatory/Five tournaments she participated in over that duration.

Floyd 'Money' Mayweather as a pro (2000-2015)

'Men lie... women lie... numbers DON'T lie.' After medalling at the 1996 Atlanta Olympics, featherweight American boxer Floyd Mayweather Jr. went professional. And as a pro, he has never been beaten. Fifty bouts. Fifty wins. Twenty-seven knockouts.

He started as 'Pretty Boy' and soon became 'Money', having beaten all comers, including Manny Pacquiao, one of the greatest professional boxers of all time, in the 'Fight of this Century'. Mayweather is a bonafide pound-for-pound great, one of the best defensive boxers of all time and one of the very few to hang up his gloves undefeated.

(If the poll doesn't load, click here to try again. The poll will close at 5PM IST on Friday, June 26)