Over the past week, GiveMeSport have conducted a series of polls to settle one of the toughest debates in sport: who is the greatest sportsman of all-time? 

To create a fair poll, 16 sporting individuals were placed into four separate groups, with the winner and runner up from each group progressing through to the semi-finals and then eventually to the final to decide the winner. 

The nominees included for group one included: Lewis Hamilton, Roger Federer, Floyd Mayweather and Serena Williams. 

Group two saw Phil Taylor, Michael Phelps, Tom Brady and Lionel Messi in a fierce battle. 

Tiger Woods, Cristiano Ronaldo, Martina Navratilova and Michael Jordan all made up group three. 

And in the final group LeBron James, Michael Schumacher, Pele and Muhammad Ali were pitted against each other.

Plenty of notable names in group one but it was Swiss sensation Federer who progressed to the next round. Federer is considered to be one of the greatest athletes to grace the sport of tennis, winning 20 Grand Slams and experiencing success at tour finals and the Olympics. 

In group two, the Argentinian genius, Messi, topped the group with an impressive 75% share of the vote make a real statement to the rest of the potential contenders.

Messi's Ballon d'Or rival, Ronaldo, topped group three defeating the likes of Phelps and Brady in the process. 

To finish, Muhammad Ali topped group four with 52% of the vote. Despite being a three-time heavyweight champion of the world, Ali transcended the sport as he tackled various societal issues which took place outside of boxing and made him such a sporting icon. 

And after the semi-final stages, it was Messi and Ali who triumphed and topped their groups with 65% and 32% of the votes respectively.

But there could only be one winner and after an extremely close battle, Messi narrowly emerged victorious by claiming 51% of the 240,800 votes received on Facebook.

It doesn't get much closer than that!

On the equivalent Twitter poll, the winning margin was similarly narrow (53%-47%) but also fell in Messi's favour.

To track the full set of results, click here to follow the Twitter thread.