Top 5 most intense individual rivalries in the history of professional sports

#1 Lionel Messi vs Cristiano Ronaldo (Football)

Real Madrid v Barcelona - La Liga

There really could be only one rivalry to top this list, as these two men have totally redefined what it means to be a professional footballer.

Ronaldo is the older of the pair and made his debut first in 2002, but despite only making his competitive professional debut two years later, Lionel Messi deserves immense praise for clawing his way into being considered arguably the best player in history.

While Ronaldo was at Manchester United, there were loud whispers of comparisons between the two, as they had each shown to be the biggest talents in their age grade at that time.

However Ronaldo's transfer to Real Madrid for a world record fee in 2009 brought their comparisons to a head, as both men now played in the same league at the same time for the two biggest clubs in the world.

Such has been their utter dominance that all individual award ceremonies in the ten years between 2008 and 2017 were duopolized into their personal battleground. Their competition has been so intense that it spawned a website dedicated to just the two's stats and records.

For nine seasons in LaLiga, Messi performed extraordinary feats, only to see them eclipsed by Ronaldo sometimes in a matter of hours and vice versa. Both players have set yardsticks, almost unspokenly daring the other to achieve or surpass it.

It was almost comical the way in which the duo set about raising the bar in their competition with one another and such was their otherworldly brilliance that every other player in the world left them in their personal game of deciding the world's best.

Ronaldo set a record of scoring against all LaLiga teams in a single season, Messi achieved the same feat the next season.

Ronaldo became the first player ever to reach the 40-league goal mark in 2011, a season later, Messi did the same and added an extra 10 goals for good measure. Messi was the first of the pair to score 50 Champions League goals and broke Raul's previous record first; Ronaldo beat him to 100.

If Messi scored a brace, you can expect Ronaldo to score a hat-trick when Real Madrid lined up.

Each of the 10 Ballon d'Ors between 2008 and 2017 were shared equally between them, each of the last 9 Champions League Golden Boots has been won by at least one of them.

Ronaldo became the first ever player to win the European Golden Shoe four times in 2015, Messi equaled that two years later and extended his record to six at the end of the recently concluded season. They each hold the record of having appeared in the most FIFPRO World XIs with 11 appearances between 2007 and 2018.

Their rivalry has been so intense that a common and rather annoying trend on social media and football websites over the last decade has been a bitter debate over who the better player is (even on unrelated posts), with fans almost equally divided in their support for the Portuguese and Argentine icons.

In total, the eternal duo have faced each other 35 times in all competitions, with Lionel Messi winning 16, scoring 21 and assisting 12 while his Portuguese rival has won 10, scored 19 and assisted one.

Despite their seeming immortality, Ronaldo and Messi would one day exit the scene, but their contributions and extraterrestrial abilities have been so far reaching that their impact on the beautiful game would still be felt for generations to come.