Sensational Thiem downs Nadal in London classic — ATP Finals

Sensational Thiem downs Nadal in London classic — ATP Finals

Tennis Grand Slam champions Rafael Nadal and Novak Djokovic are once again at loggerheads while holding opposing views regarding whether or not Grand Slams should be changed from best-of-5 rules to best-of-3.

Former champion Alexander Zverev ground out a win against debutant Diego Schwartzman to click up his first win in the tournament.

There was little sign of what was to come in a mesmerising opening to the match as Djokovic edged into a 3-2 lead. The first break came after a marathon game when the Russian finally converted his third break point when Djokovic missed a forehand after a long rally.

(CNN)Daniil Medvedev produced a brilliant display to beat world No. 1 Novak Djokovic in straight sets, 6-3 6-3, at the ATP Finals on Wednesday.

Djokovic then double-faulted on set point and never looked likely to stage a comeback in the second.

It was a surprise when Rublev broke to level the match, a string of unforeseen errors from Tsitsipas giving up three set points.

"It was much better than on Monday", said Zverev.

"[It was] a great match of tennis decided [by] a few small details. I don't think he played better than me, although he deserved it ". "I am sure being with that mindset, being willing to just put more and more effort into what I am doing and more sacrifices are going to pay off at the end", he added. "Well, not the case". The story is the same so far this week, as the world No. 3 has already wrapped up Group B thanks to victories over Tsitsipas and Nadal.

A visibly frustrated Zverev fired a ball into the empty stands after losing the second set.

If the 34-year-old plays anywhere close to his level against Thiem, it should be enough to once again break down the Tsitsipas backhand and send him through to the semis. An unforced error from Rublev lofting a forehand out sets up another opportunity, 3rd chance now for Tsitsipas, which the Greek can't take resetting the score back to deuce.

While Medvedev will go into his final group match against Diego Schwartzman with no stress, Djokovic faces a straight shoot-out with Zverev to avoid an early exit.

"I think I did all the things well during the match".

The German appeared to lose focus though and Schwartzman grabbed his chance to win five of the next six games and extend the match into a decider.

While Thiem eyes a last four berth, Nadal will have to beat Tsitsipas in his last group match to keep alive his hopes of reaching the semi-finals.

Even when Tstsipas was at his best last fall and went on to lift the trophy inside the O2 Arena, he still lost to Nadal during round-robin action via a 6-7 (4), 6-4, 7-5 decision.

The O2 Arena is hosting the ATP Finals for the 12th and final season before the year-end championships moves to Turin next year.