Where are they now? Wozniacki, Williams and the players to scale the WTA heights
Caroline Wozniacki's rise back to the pinnacle of women's tennis after winning the Australian Open continued a familiar trend of the world number one spot being shared around on the WTA Tour.
While the top spot in the ATP rankings has been monopolised by the 'Big Four' of Roger Federer, Rafael Nadal, Novak Djokovic and Andy Murray since November 2003, the right to be called best in the world has been shared around much more readily in the women's game.
No fewer than 14 players have been top ranked in the same period, with five players having held the position since Serena Williams relinquished the moniker having had her first child last year.
Below we look at where the 10 active female players that have been world number one are now...
Caroline Wozniacki: 1
Wozniacki not only ended her major drought in Melbourne via an emotional win over Simona Halep, but it capped a sensational rise back to world number one. The Dane first achieved the accomplishment in October 2010 and was displaced at the top for just one week in a remarkable 2011 that yielded six titles but no major breakthrough. A loss of form saw her fall as low as 74 in 2016, but she has steadily regained top spot.
Simona Halep: 2
Arguably the most talented player on the WTA Tour yet to win a major, but it has not been for a want of trying for Halep. The skilful Romanian has twice lost in the French Open final, and was of course the unlucky loser to Wozniacki in Melbourne. Halep reached the summit of the women's game in October 2017, is second now only to Wozniacki, and will surely win a slam before too long.
Garbine Muguruza: 4
One of the most gifted players on the Tour, Muguruza's versatility is shown by the fact that her two grand slam triumphs have come at the French Open and Wimbledon, the latter coming against the great Venus Williams in 2017. Her triumph at SW19 was one that helped propel her to top spot last September, but she was usurped a month later by Halep and is now ranked fourth.
Karolina Pliskova: 5
Another gifted player without a slam, and another to have benefitted from Serena William's hiatus is Pliskova. A run to the final of the 2016 US Open is the closest she has come to winning one of tennis' big four, and she clinched a first world number one berth in July 2017 after Angelique Kerber's loss of form.
Venus Williams: 8
One half of a Williams sisters dynasty that has reigned in women's tennis for two decades. Venus was the first of the fearsome siblings to become number one in February 2002, and she has been ranked top on three occasions. While Serena has cemented her status as one of the greatest, Venus still has a career to be proud of with seven slams to her name and, at the age of 36, is still going strong as world number eight.
Angelique Kerber: 9
Kerber's career was largely one of failed promise until a stunning 2016, which started with victory at the Australian Open, saw her reach the final of Wimbledon, and finish the year by triumphing at the US Open. The German ended Serena Williams' 186-week stranglehold of top spot and went back-and-forth with the American in the early stages of 2017. A loss of form last year saw Kerber drop to 22 by the start of January, but more promising showings since have resulted in a return to the top 10.
Maria Sharapova: 41
Sharapova is a star that has transcended tennis, and the Russian has enjoyed a glittering career that has returned five grand slams and four stints as world number one. However, a 15-month doping ban saw her drop to as low as 262 by the start of January 2017. Since then, Sharapova has climbed back inside the top 50.
Victoria Azarenka: 207
A two-time Australian Open champion, Azarenka displaced Wozniacki atop the rankings in January 2012 and had another stint at the top, which preceded Serena Williams' monopoly between February 2013 and September 2016. The Belarusian was involved in a custody battle over her son Leo and a lack of activity since last year's Wimbledon has seen her plummet outside of the top 200.
Jelena Jankovic: 235
Jankovic was one of the dominant forces in women's tennis towards the end of the previous decade, and spent the majority of the second half of 2008 as world number one. However, the Serbian was unable to win a slam in that period - coming closest at the 2008 US Open where she reached the final - and a combination of injury and poor form has seen Jankovic crash out of the world's top 200.
Serena Williams: Unranked
There is little left to be said about one of the greatest sportspeople of all time. Serena has been the dominant force in women's tennis, racking up an astonishing Open-era record of 23 grand slams. On eight occasions Williams has been the top-ranked player, including the previously mentioned remarkable 186-week run between 2013 and 2016. Having spent time away from court due to the birth of her child Alexis Olympia last year, Williams is currently unranked - but few would bet against her regaining her throne once again.