Novak Djokovic defeats Stefanos Tsitsipas on Sunday in Astana.

Novak Djokovic in action on Sunday in Astana.

Nikola Mektic and Mate Pavic celebrate winning the title in Astana.

Novak Djokovic in action on Saturday in Astana.

Stefanos Tsitsipas earns his 53rd tour-level win of the season on Saturday in Astana.

Novak Djokovic in action against Daniil Medvedev on Saturday in Astana.

Daniil Medvedev in action on Saturday in Astana.

Stefanos Tsitsipas is seeking his third tour-level title of the season this week in Astana.

Novak Djokovic is seeking his fourth tour-level title of the season this week in Astana.

Stefanos Tsitsipas in action on Friday in Astana.

Novak Djokovic in action against Botic van de Zandschulp on Thursday in Astana.

Novak Djokovic celebrates his straight-sets win against Botic van de Zandschulp on Thursday in Astana.

Stefanos Tsitsipas celebrates defeating #NextGenATP Italian Luca Nardi at the Astana Open on Wednesday.

Novak Djokovic in action against Cristian Garin at the Astana Open on Wednesday.

Luca Nardi strikes a forehand during his win against David Goffin in Astana qualifying on Sunday.

Novak Djokovic practises in Astana on Tuesday in preparation for his first-round match against Cristian Garin.

Daniil Medvedev wins 48 per cent of his return points to defeat Albert Ramos-Vinolas in Astana.

Carlos Alcaraz suffers his first straight-sets loss of the year on Tuesday against David Goffin in Astana.

Andrey Rublev smiles during his first-round match on Monday in Astana.

David Goffin defeats Carlos Alcaraz on Tuesday in Astana.

Stefanos Tsitsipas earns his 50th tour-level win of the season on Tuesday in Astana.

Carlos Alcaraz in Astana is playing his first ATP Tour event as the World No. 1 in the Pepperstone ATP Rankings.

Novak Djokovic and Carlos Alcaraz speak with children at ‘Asyl Miras’, an autism centre in Kazakhstan.

Felix Auger-Aliassime and Daniil Medvedev visit ‘Asyl Miras’, an autism centre in Kazakhstan.

Karen Khachanov will pursue his fifth ATP Tour title this week in Astana.