'Remarkable': Star's sneaky act divides tennis fans

World no.7 Alexander Zverev has offered a bizarre explanation for a video clip which appears to show him checking his phone, or some other electronic device, during his ATP Finals match against Stefanos Tsitsipas.

The German 22-year-old fell to Tsitsipas 6-3 6-2, missing a chance to qualify for the semi-finals.

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Zverev’s loss was not the major talking point of the match though, with the German star insisting he had not been looking at his phone.

Players are banned from bringing any electronic devices on the court with them when they play.

Instead, Zverev claimed he had simply been fiddling with a water bottle in his bag.

“It wasn’t a phone,” he said.

Alexander Zverev has batted away accusations he was checking his phone or some other device during his ATP Finals match against Stefanos Tsitsipas. Picture: Twitter/Ben Rothenberg

“My phone was in the locker room. I don’t know what it was. Maybe a water bottle.”

Unfortunately for Zverev, fans weren’t copping his explanation.

Rafael Nadal's insane '1 in 1000' ATP Finals comeback

Rafael Nadal gave himself a ‘one in 1000’ chance of claiming an unlikely comeback win over Daniil Medvedev at the ATP Finals overnight.

The Spanish superstar had won a close first set but dropped the second, and Medvedev had been on a tear since.

Nadal was facing a match point, down 1-5, when he gave himself an outside shot at coming back.

In doing so, he once again proved himself a champion, rattling off five straight games before two errors from Medvedev in the tiebreak handed him a memorable 6-7 (3), 6-3, 7-6 (4) victory.

“Today is one of those days that one out of 1,000 you win and it happened today,” Nadal said.

“(facing match point) In that moment, what you think is probably in five minutes you are in the locker room, because that’s the more normal thing. In that moment, you play with not much pressure because you are almost lost.”