Australian Open 2019: Kei Nishikori survives clash with Pablo Carreno Busta

A furious Pablo Carreno Busta has blown up at the chair umpire after losing to Japan's Kei Nishikori in a five-hour epic during the Australian Open round of 16.

Eighth seed Nishikori trailed by two sets and a break but fought back magnificently to claim a marathon 6-7 (8-10) 4-6 7-6 (7-4) 6-4 7-6 (10-8) victory on Margaret Court Arena.

Up 8-5 in the first-to-10 points deciding tiebreaker, Carreno Busta raged at the chair umpire after Nishikori was awarded a point - hitting a winner off a ball initially called out - that the Spaniard was adamant should have been replayed.

The official was unmoved and Nishikori won the next four points, firing off an ace to claim victory and equal his best Australian Open result.

Carreno Busta shook hands with Nishikori before throwing his bag across the court and again screaming at the umpire before departing to scattered boos.

It is the third five-set match Nishikori has been forced to endure for the tournament, taking his time on court to almost 14 hours.

"I don't know what to say now. Very tough match," he said.

"Of course I was disappointed to lose the first and second sets but I tried to be positive. I just need to recover well. I've been playing really good tennis so I'll try to be fresh for the next match and hope I can have one more good week."

Nishikori will next face world number one Novak Djokovic, who survived a taxing fourth-round clash with rising star Daniil Medvedev to edge closer to his seventh Australian Open title.

In a grinding encounter on Rod Laver Arena that stretched into the early hours of Tuesday morning, Djokovic outlasted his 22-year-old opponent to claim a hard- fought 6-4 6-7 (5-7) 6-2 6-3 victory in three hours and 15 minutes.

Frenchman Lucas Pouille earlier continued his career-best run at the Australian Open, defeating Croatian 11th seed Borna Coric to advance to the quarter-finals.Pouille, who beat Australian teenager Alexei Popyrin in a five-set thriller in the third round, prevailed against Coric 6-7 (4-7) 6-4 7-5 7-6 (7-2) on Monday night.

The 24-year-old had never won a match at Melbourne Park before this year's tournament.

His reward is a showdown with Canada's Milos Raonic, who earlier dismantled fragile German fourth seed Alexander Zverev 6-1 6-1 7-6 (7-5).               

AAP 

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