Penpix of the top men's contenders at the 2021 Australian Open:
Novak Djokovic (Serbia)
World ranking: 1
Born: May 22, 1987 (Age: 33)
Grand Slam titles: 17 (Australian Open 2008, 2011, 2012, 2013, 2015, 2016, 2019, 2020); French Open 2016; Wimbledon 2011, 2014, 2015, 2018, 2019; U.S. Open (2011, 2015, 2018)
Best Australian Open performance: Winner (2008, 2011, 2012, 2013, 2015, 2016, 2019, 2020)
ATP career titles: 81
Djokovic returns to his favourite hunting ground in search of a record-extending ninth Australian Open title and 18th Grand Slam crown which would reduce the gap to his nearest rivals Roger Federer and Rafa Nadal to two majors.
The rubber-limbed Serb's precise groundstrokes are at their most dangerous on Melbourne's fast hard courts, where he has dominated for the last decade, winning seven of the past 10 editions.
Djokovic looked primed for one of the most successful seasons in tennis history last year when he embarked on a 26-0 winning run.
But his disqualification at the U.S. Open for inadvertently hitting a line judge with a ball and thrashing by Nadal in the French Open final took some of the shine off and he will head to Melbourne Park with a point to prove.
Dominic Thiem (Austria)
World ranking: 3
Born: Sept. 3, 1993 (Age: 27)
Grand Slam titles: 1 (US Open 2020)
Best Australian Open performance: Runner-up (2020)
ATP career titles: 17
After several years spent knocking on the door, Thiem joined the Grand Slam winners' club last year when he claimed the U.S. Open title in spectacular fashion, overturning a two-set deficit against Alexander Zverev in the final.
The Austrian baseliner reached the showpiece match at Melbourne Park last year only to lose to Djokovic in a thrilling final and he will hope to go one better this time around.
While clay is his preferred surface, Thiem has enjoyed some of his best results on hard courts. His powerful groundstrokes and physical conditioning make him one of the top contenders at the year's first major.
Daniil Medvedev (Russia)
World ranking: 4
Born: Feb 11, 1996 (Age: 24)
Grand Slam titles: 0
Best Australian Open performance: Fourth round (2019, 2020)
ATP career titles: 9
Medvedev enters the Australian Open as the member of the next generation best poised to make his breakthrough, having captured the biggest title of his career - the ATP Finals - at the end of last season.
Medvedev's imaginative and unorthodox game, which combines sledgehammer power with extreme angles and a cannonball serve, can prove particularly effective on Melbourne's faster hard courts.
The volatile Russian thrives on the big stage and boasts a seven-match winning streak against top 10 players.
Rafael Nadal (Spain)
World ranking: 2
Born: June 3, 1986 (Age: 34)
Grand Slam titles: 20 (Australian Open 2009; French Open 2005, 2006, 2007, 2008, 2010, 2011, 2012, 2013, 2014, 2017, 2018, 2019, 2020; Wimbledon 2008, 2010; U.S. Open 2010, 2013, 2017, 2019)
Best Australian Open performance: Winner (2009)
ATP career titles: 86
The Australian Open has proved to be Nadal's least successful Grand Slam, with the Spaniard last winning the season-opening major 12 years ago.
Nadal, who drew level with Federer's record of 20 Grand Slam titles last year, arrives at Melbourne Park this time relatively free of injuries and with the added motivation of becoming the most successful player in men's tennis.
His whipped topspin forehand is one of the most vicious shots in tennis and Nadal has also developed more bite on his serve, making him all the more difficult to subdue.
Stefanos Tsitsipas (Greece)
World ranking: 6
Born: Aug. 12, 1998 (Age: 22)
Grand Slam titles: 0
Best Australian Open performance: Semi-finals (2019)
ATP career titles: 5
Tsitsipas ended 2019 by winning the coveted ATP Finals crown but failed to build on that triumph last year, suffering third-round exits at the Australian and U.S. Open before a semi-final showing at Roland Garros.
With an exciting all-round game and incredible athleticism, Tsitsipas has become the player to watch on the men's tour.
He will enjoy strong support from the large Greek community in Melbourne in his quest to become the first Grand Slam champion from his country.
Alexander Zverev (Germany)
World ranking: 7
Born: April 20, 1997 (Age: 23)
Grand Slam titles: 0
ATP career titles: 13
Best Australian Open performance: Semi-finals (2020)
In a topsy-turvy 2020 campaign, Zverev reached his maiden Grand Slam showpiece match at the US Open, won two ATP titles and made the final of the Masters 1000 event in Paris, although his season was marred by allegations of domestic abuse by his former girlfriend, which he denied.
The German possesses a fiery first serve and rock-solid backhand but his feeble forehand and shaky second serve often prove to be his undoing.
Zverev, who recently split with coach David Ferrer, is bidding to become the first German man to win the Australian Open since Boris Becker in 1996.