Angelique Kerber changes coaches in a bid to revive career

Angelique Kerber, who started 2017 as the world No. 1 but has since plunged down the rankings to 21, announced via Twitter on Thursday that she was parting ways with longtime coach Torben Beltz for a second time.

Beltz first began working with Kerber when she turned professional in 2003 but the two first went their separate ways following the 2013 season, when she hired Benjamin Ebrahimzadeh as her new coach. However, she rehired Beltz after getting off to a poor start in 2015 and it was under him that she won the 2016 Australian Open and climbed to the top of the women's rankings by winning her second Grand Slam,the US Open.

Kerber, 29, also used Twitter to announce that she had hired Wim Fissette as her new coach.

Fissette, a 37-year-old native of Belgium, has previously worked with a number of top women's players, including Kim Clijsters, Simona Halep, Victoria Azarenka and most recently Johanna Konta.

Following her sensational 2016, Kerber failed to win a single tournament in 2017, only making to one final (Monterrey). The lefthander's next tournament is the Hopman Cup in Perth, which begins on December 30. She is to form half of the German team, along with Alexander Zverev.