'This is no joke': Staggering Rafael Nadal feat stuns tennis world

If the world needed further proof about how good a frontrunner Rafael Nadal is, then the Spaniard put forward an emphatic reminder at the ATP Finals in London.

Nadal kept alive his hopes of winning the year-ending indoor event for the first time as he beat Greek defending champion Stefanos Tsitsipas 6-4 4-6 6-2.

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The last round-robin match in the London Group was a straight knockout with both men losing to Austria's Dominic Thiem and having beaten Andrey Rublev earlier in the week.

But it was the Spaniard who always appeared the likely winner despite a lapse which allowed Tsitsipas to extend the contest into a decider at a near-deserted O2 Arena.

Based on Nadal’s form over the last year, the result was almost a foregone conclusion as soon as he’d taken the first set against the Greek star.

The Spaniard went into the clash on an extraordinary 70-match winning streak from matches where he’s won the opening set.

Remarkably, Nick Kyrgios was the last man to win a match against Nadal when the Spaniard has taken the first set.

The Aussie accomplished the feat during their now infamous Mexico Open clash in Acapulco that kickstarted an ugly feud between the pair.

Following his three-set win against Tsitsipas, it’s now an incredible 71 matches in a row that Nadal has won as a frontrunner.

The extraordinary statistic has left tennis fans gobsmacked on social media.

Nadal into first semi-final since 2015

After a flurry of service breaks at the start of the third set, the 34-year-old Nadal pulled away to reach the semi-finals for the first time in five years.

As group runner-up behind Thiem, he will face Daniil Medvedev for a place in the final with the Russian assured of top spot in the Tokyo Group.

"In general this was a very positive match for me," said Nadal, who despite winning 20 Grand Slam titles has only two runners-up places to show for his previous nine appearances at the ATP Finals.

"Excited to be in the semi-finals."

Tsitsipas, who enjoyed his breakthrough moment here last year when, was downbeat about his performance.

"I fought hard in the second set but very disappointed with the third, I was rushing and didn't know what I was trying to do honestly. I should have been a bit more clever," the 21-year-old said.

Russian youngster Rublev signed off from his maiden ATP Finals in impressive fashion by beating Thiem 6-2 7-5.

The aggressive 23-year-old took full advantage of a rather flat performance by Thiem, who had already sealed his place in the final four with two group wins.

Rublev was playing only for pride, although the $US153,000 ($A210,484) bonus for a group stage win provided a sizeable incentive.

"It was not easy for Dommy," said the world No.8, who won a tour-leading five ATP titles this year.

"I think he (was) focused on the semis. I wish him good luck - he deserves to be where he is and he deserves to win the title."

Thiem will shrug off the defeat and now has a day off to prepare for Saturday's semi-final when he will face either world No.1 Novak Djokovic or Alexander Zverev.

with AAP

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