A little over 12 months ago, with Rafael Nadal and Roger Federer having won 25 of the past 30 Grand Slam tournaments between them, there was a sense or order at the top of the order of men's tennis.
Federer and Nadal had fought out several epic battles over the years and while the Swiss has won 16 Grand Slam, the Spaniard held the edge on head to head, winning 17-9.
Perhaps most surprisingly, while the two shared an intense rivalry across the net, they were anything but enemies of the court. An entente cordiale between the parties is probably the product of a modern age, born of marketing and image.
Nadal was canny enough to realise that being the young upstart of the two, he had little hope of turning the fans against the amiable Roger, who has already established himself not only as the most dominant player seen in a generation, but also the Mr Nice Guy of the sport.
Any enmity, artificial or otherwise between the pair was likely to reflect badly on the Spaniard, so he came bearing gifts not guns and the relationship between them was mutually beneficial.
It became more commercially viable for the two men to be seen as friends than it did portraying them as enemies.
It was an intriguing arrangement and one that saw them both promoted as different faces on elite tennis, and different brands for their sponsor Nike. From a marketing point of view, this wasn't a Coke v Pepsi war, this was a choice between two brands essentially from the same stable. It was Coke v Fanta or Sprite.
In a move which has few parallels in the world of sport, they worked together to further their own brands whole continuing an on court rivalry which yielded them both plenty of success.
But this depended on the two of them remaining the clear top two in the world. There had been brief challenges to their ascendency over the latter half of the 2000s, with Marat Safin winning the Australian Open in 2005, Novak Djokovic claiming a debut Grand Slam at the same event in 2008 and Juan Martin Del Potro upsetting both on his way to winning the 2009 US Open.
But at the start of 2011, despite Federer approaching his 30th birthday and Nadal his 25th, there was no clear end in sight for the Federer-Nadal era and the comfortable relationship in which they shared the spotlight.
However, Djokovic's win in Melbourne in 2011 changed all that. A joker in the pack, if you will, he had always threatened to take that next step and his stunning 2011 turned the men's game on its head.
Not only that, but he was much more brash than either Nadal or Federer. He is not afraid to stand on toes, and ruffled Federer's feathers with his distinct sense of humour, which included an impersonation of the Swiss master.
His wins at the Australian Open, Wimbledon and the US Open have given his a real voice of credibility in men's tennis and as a result, both Federer and Nadal seem distinctly put out.
It also acted as a short circuit to the comfortable relationship enjoyed between what used to be the world's two best tennis players.
The players' meeting on the eve of this Australian Open proved a flashpoint for this relationship.
Federer was criticised for