Mubadala World Tennis Championship: The story so far for Novak Djokovic, Rafael Nadal and Maria Sharapova - in pictures

How the drama of the event has unfolded in Abu Dhabi

Rafael Nadal during his semi final against Karen Khachanov at the Mubadala World Tennis Championship. Chris Whiteoak / The National

The National's booth during the Mubadala World Tennis Championship. Chris Whiteoak / The National

Spain's Rafael Nadal in action during his semi final match against Russia's Karen Khachanov. Reuters

Rafael Nadal shakes hands with Karen Khachanov after his 6-1, 6-3 semi-final victory. Chris Whiteoak / The National

Karen Khachanov celebrates winning a point during the semi final against Nadal. Chris Whiteoak / The National

Khachanov serves against Nadal. Chris Whiteoak / The National

Nadal during the semi-final against Karen Khachanov. Chris Whiteoak / The National

Novak Djokovic looks to the sky during his semi final against Stefanos Tsitsipas at the Mubadala World Tennis Championship. Chris Whiteoak / The National

Fans enjoy the semi-final between Novak Djokovic v Stefanos Tsitsipa. Chris Whiteoak / The National

Stefanos Tsitsipas celebrates after winning the semi final against Novak Djokovic. Chris Whiteoak / The National

Stefanos Tsitsipas during the semi final. Chris Whiteoak / The National

Novak Djokovic won the first set against Stefanos Tsitsipas before losing 3-6, 7-6, 6-4 in their Mubadala World Tennis Championship semi-final. Chris Whiteoak / The National

Andrey Rublev during his fifth place play-off win, 7-6, 7-6, against Hyeon Chung at the Mubadala World Tennis Championship. Chris Whiteoak / The National

Hyeon Chung serves during the fifth place play-off against Andrey Rublev. Chris Whiteoak / The National

Maria Sharapova celebrates during her match against Ajla Tomljanovic. Chris Whiteoak / The National

Maria Sharapova in action against Ajla Tomljanovic. She won the match 6-4, 7-5. Chris Whiteoak / The National

Ajla Tomljanovic was beaten by Maria Sharapova. Chris Whiteoak / The National

Maria Sharapova sigs autographs after her win v Ajla Tomljanovic. Chris Whiteoak / The National

Karen Khachanov during his opening match against Hyeon Chung, which he won 7-6, 6-4. Chris Whiteoak / The National

Hyeon Chung plays a shot during the match against Karen Khachanov. Chris Whiteoak / The National

Stefanos Tsitsipas in action in his win against Andrey Rublev on day one. Chris Whiteoak / The National

Andrey Rublev hits a shot against Stefanos Tsitsipas. The Greek won 6-3, 6-4. Chris Whiteoak / The National

Stefanos Tsitsipas hits a ball into the crowd after his opening day win. Chris Whiteoak / The National

The Mubadala World Tennis Championship has been another resounding success as some of the world's top players battle for supremacy.

As the tournament heads for a thrilling climax, the crowds in Abu Dhabi have been entertained by some top class action.

Novak Djokovic and Rafael Nadal play again on the final day again on Saturday.

Djokovic faces Karen Khachanov in the third place play-of, and Nadal takes on Greek Stefanos Tsitsipas for the title.

Here, in pictures, is how the tournament has unfolded so far before the conclusion gets underway.