When Roger Federer was dominating tennis during the early 2000s, it seemed as though nothing would stand in his way to greatness.
With Pete Sampras on the wane before his retirement, and Leyton Hewitt and Andy Roddick simply not on Federer's level, there were fears that no great pretender would ever step up to the plate. Concerns existed that virtually every major would be a one-horse race.
Yet then came Nadal, with his bulging biceps and immaculate long hair. After winning the French Open in 2005 to claim his first Grand Slam title, a star was born.
The tennis world is currently in mourning after the veteran confirmed on Thursday that his time in the sport was up. Once next month's Davis Cup finals are out of the way, he will embark on a well-deserved rest.
Rafael Nadal tribute: Tennis icon has confirmed his retirement from the sport after writing his name into the history books
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Nadal, simply put, is a legend of the sport.
With 22 Grand Slams to his name, he will walk away with two more than Federer. Novak Djokovic is the only man with more, with the Serb claiming 24 throughout his own career so far.
Nadal has had to play in arguably the toughest era of them all. In addition to Federer and Djokovic, he once had to contend with a prime Andy Murray.
Then there's Stan Wawrinka and Juan Martin del Potro, who would likely have won more majors themselves if it wasn't for constant injury issues. Don't forget about Carlos Alcaraz, who has been a threat over the past three years - with four majors claimed in that time.
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Yet no matter what has been thrown at him, Nadal has displayed gladiatorial qualities to write his name into the tennis history books.
When he started to dominate the French Open, there was the big question over whether he could shine on grass and hard-court surfaces as well.
With Nadal losing his first two Wimbledon titles to Federer in 2006 and 2007, there was a sense that he'd maybe only be a one-surface player.
Yet all that changed in 2008 when he upset the odds to beat Federer in arguably the best Wimbledon final of all time.
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Having thrown away a two-set lead, Nadal could have been forgiven for letting the pressure get to him.
However, the very best champions still find a way to win. That's exactly what the 38-year-old did, with Nadal finally managing to see off Federer as darkness started to engulf Centre Court.
Six months later, Nadal then left his rival reeling as he won the Australian Open. Federer, starting to fear his powers weren't capable of producing the same moments of greatness as before, was reduced to tears as his hopes of glory went up in smoke.
With three different Grand Slams to his name, the career Slam was always destined to follow.
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Rafael Nadal tribute: Tennis icon has won a staggering 22 Grand Slam titles throughout his career
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And Nadal achieved that feat in 2010, beating Djokovic to claim victory in a pulsating US Open final.
It is an open secret that his knees, for the bulk of his career, have caused him severe discomfort.
In 2009, in particular, there was even talk of Nadal retiring. He was forced to withdraw from the French Open and was then unable to mount a defence of his Wimbledon title in a huge, devastating blow.
Yet fast-forward to now and Nadal has cemented himself as a tennis icon, a player for all surfaces and a champion who deserves every bit of recongition coming his way.
Rafael Nadal tribute: Tennis maestro deserves all the plaudits after his decision to retire
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His dominance of the French Open was remarkable. His record of 14 Grand Slams at Roland Garros will likely never be beaten.
But his ability to rise above adversity, to conduct himself with grace, to play with swagger, to enchant Grand Slam tournaments at Wimbledon, the US Open and Australian Open, to win two Olympic golds and to keep bouncing back no matter what is what makes him such a legendary figure.
The tennis world will miss him.