#4 Roger Federer (2004, 2006-07, 2010, 2017-18)
The Australian Open has been one of the happy hunting grounds for Federer during his illustrious career.
Federer's second Grand Slam title, and first at the Australian Open (2004), was the precursor to the Swiss maestro becoming the 23rd different player in the ATP rankings to hold the No. 1 position. He then squandered a match point in a five set 2005 semifinal loss to eventual winner Marat Safin, before returning to pick up consecutive titles in 2006-07.
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The 2007 title was only the second instance (Ken Rosewall - 1971 being the first) of a player winning the Australian Open without dropping a set.
Federer lost to Novak Djokovic in the 2008 semis before suffering his only Australian Open final defeat in 2009, as he went down to an inspired Rafael Nadal in five sets. A fourth title in 2010, following a straight-sets win over Andy Murray in the final, moved Federer level with Andre Agassi for most titles at the tournament in the Open Era.
Although Federer wouldn't reach another title match at the tournament for seven years, the Swiss maestro created a new record for most consecutive semifinals at the Australian Open. He did so on an 11th consecutive occasion in 2014, before losing to Andreas Seppi in the third round in 2015.
Following a four-set semifinal loss to eventual winner Djokovic in 2016, Federer beat his nemesis Nadal in a five-set 2017 final to win a record-extending 18th Grand Slam title - four and a half years after winning his 17th at 2012 Wimbledon.
A year later, Federer prevailed over Marin Cilic in five sets to become the oldest player (36 years) to successfully defend his title at the Australian Open. He then lost to Stefanos Tsitsipas in a four-set fourth round clash in 2019.
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