'Not seen this before': Tennis star storms off court in 'ridiculous' ATP Cup tantrum

Pablo Cuevas was at the centre of a bizarre controversy at the ATP Cup on Wednesday night, walking off the court mid-match over a row with the chair umpire.

The Uruguayan was left fuming during his clash with Georgian opponent Nikoloz Basilashvili when the umpire warned him he wasn’t showing enough effort.

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Despite the score being 5-4 in the first set, the chair umpire told Cuevas to lift his game or he would receive a code violation.

Cuevas then decided to mock the umpire by over-exaggerating his every move when he returned for to the court for the 10th game of the set.

He sprinted to his position at the baseline, did a number of massive jumps on the spot and greatly exaggerated his effort to return Basilishvili’s serves.

But the 34-year-old was left incensed when the umpire hit him with a code violation anyway for unsportsmanlike conduct.

Cuevas called for the match supervisor before packing his bags and storming off court following a heated discussion.

Only the intervention of Basilishvili prevented Cuevas from heading back to the locker room, his opponent convincing him to keep playing.

It nearly backfired on Basilishvili when Cuevas took the second set 6-1, but the Georgian managed to prevail 6-4 1-6 6-4.

Nadal and Djokovic lead teams into quarter-finals

Serbian spearhead Novak Djokovic will enter the ATP Cup quarter-finals in hot form, but world No.1 Rafael Nadal needs to shake off some rust if Spain are to live up to their pre-tournament favouritism.

Nadal was made to work for his 7-6 (7-4) 6-4 win over world No.72 Yoshihito Nishioka in Perth, committing 36 unforced errors along the way.

The hard-fought win wrapped up the tie for Spain and secured their spot in the last eight after world No.10 Roberto Bautista Agut beat Japan's Go Soeda 6-2 6-4 earlier in the day.

Nadal and Pablo Carreno Busta then teamed up to break Japanese hearts with a third-set super-tiebreaker win over Ben McLachlan and Go Soeda to eliminate the Asians from the tournament.

Nadal won all three of his singles matches in straight sets during the group stage, but he has lacked his usual ruthless edge and accuracy at times.

The 19-times grand slam champion led Spain to Davis Cup glory in November, and he's keen to add the ATP Cup crown to his bulging trophy cabinet.

Serbia were already assured of a spot in the last eight heading into their final tie, and Djokovic added an exclamation point with a 6-3 6-3 win over Chilean Christian Garin.

Dusan Lajovic had given Serbia a 1-0 lead in the tie with a 6-2 7-6 (7-3) win over Nicolas Jarry earlier on Wednesday.

Spain, Serbia, Australia and Russia all enter the knockout stages unbeaten.

Australia face Great Britain in Thursday's opening quarter-final at Sydney Olympic Park Tennis Centre, before Russia take on Croatia, who progressed as Group E winners on Wednesday without out even hitting a ball.

with AAP