Greece's promising tennis player Stefanos Tsitsipas on Sunday secured a seat in the Australian Open quarterfinals, having upset the two-time defending champion Roger Federer of Switzerland 6-7(11-13), 7-6(7-3), 7-5, 7-6(7-5).

Novak Djokovic has lost surprisingly to the world number 24, Roberto Bautista Agut, 6-3, 6-7 (8/6), 6-4 in the Qatar Open semifinal.

Serbia's Novak Djokovic defeated defending champion Kevin Anderson of South Africa 4-6, 7-5, 7-5 to win the Mubadala World Tennis Championship for the fourth time.

Alexander Zverev has become the first German tennis player to win ATP finals in last 15 years. He outlasted Roger Federer in semi-finals and then Novak Djokovic in the finals. Here is all you need to know about the 21-year-old tennis player.

Shocking Novak Djokovic 6-4, 6-3, Alexander Zverev won the precious ATP finals trophy on Sunday.

Alexander Zverev became the first German tennis player since 1996 to make it to the title match of the season-ending ATP Finals, after stunning Swiss star Roger Federer 7-5, 7-6 (7-5) in the semifinal.

Croatian Marin Cilic beat American John Isner, coming from a set down, and achieved his first victory at the ATP Finals in London.

World number 3 Novak Djokovic breezed into the third round of ATP Shanghai Masters on Tuesday, beating Jeremy Chardy of France in straight sets 6-3, 7-5. The 14-time Grand Slam champion, who received bye into second round, broke twice at the first set and held out all his service games to make it 6-3 in 34 minutes, Xinhua news agency reported. In the second set, Chardy saved a match point at 6-5 but then made an irretrievable mistake at the net. Djokovic didn't miss the second match point with strong returning to seal the victory. "After the surgery I was not managing to play my best, and that has changed. I think I'm very close to my best. I think I'm a completely different player than I was in first five, six months of the year," said the 31-year-old Serbian, who had elbow surgery at the start of the season. Now Djokovic is back in winning form and aims for his fourth title in the Masters 1000 showpiece. "Hopefully the outcome can be different as well," he said. Earlier, the home favorite Zhang Ze was defeated by Daniil Medvedev in a nail-biter 3-6, 7-6(6), 6-4 battle. The Chinese wild card entry had chances to end the match in the second set but committed a few decisive unforced errors. Medvedev next will play top seeded Roger Federer in the second round on Wednesday "It's really a pity that today I lost the match. I played well, but I didn't win. That's why I say I regretted the result," Zhang said. In other matches, world number 6 Marin Cilic crashed out in the second round after a 2-6, 7-6(6), 7-5 loss to Chile's Nicolas Jarry, while Matthew Ebden of Australia upset world number 7 Dominic Thiem 6-4, 6-7(8), 7-6(4) in the two hours and 46 minutes grueling match. The Newly-crowned China Open champion Nikoloz Basilashvili, who ranked in career-high world number 23, eased past Canada's Denis Shapovalov 6-2, 6-2. He will face fourth-seeded Alexander Zverev in the second round.

Novak Djokovic of Serbia has defeated the third seed Juan Martin del Potro of Argentina in straight sets to claim his third US Open men's singles title. Djokovic, the sixth seed, tamed the Argentine big artillery 6-3, 7-6 (4), 6-3 in three hours and 15 minutes, here on Sunday, Xinhua news agency reported. This is Djokovic's second straight Grand Slam singles title this season following Wimbledon 2018 and a 14th overall to tie American Pete Sampras for third all-time.

In the final game of US Open 2018, 20-year-old Naomi Osaka stunned legendary Serena Williams to win her maiden Grand Slam at the Flushing Meadows. The Japanese tennis player took away the game with a straight set win of 6-2 and 6-4.

The young Japanese Naomi Osaka, champion of the US Open, received her trophy with tears before the booing of the public, which favoured the American Serena Williams.

Former world number one Serena Williams was the centre of all attention at Flushing Meadows despite having lost the US Open final to young Japanese rising star Naomi Osaka (6-2, 6-4) in a match mired in controversies and penalties.

A huge controversy has engulfed a US Open final game between Serena Williams and Naomi Osaka, won by the latter. Defending her actions on the field, Serena Williams came out in open to slam their chair umpire Carlos Osaka; she mentioned that she did not cheat in the women’s singles final against Naomi Osaka on Saturday.

Sixth seed Novak Djokovic defeated Marton Fucsovics 6-3, 3-6, 6-4, 6-0 to reach the second round of the US Open tennis tournament here.

Second seed Roger Federer started his US Open appearance with an overwhelming 6-2, 6-2, 6-4 win against Japan's Yoshihito Nishioka to enter the second round.

Romania's Simona Halep continued to lead the Women's Tennis Association (WTA) singles rankings released on Monday with 8,061 points, followed by Denmark's Caroline Wozniacki.

Spain's Rafael Nadal maintained the no. 1 spot in the men's Association of Tennis Professionals (ATP) world singles rankings released on Monday with 10,040 points, ahead of Switzerland's Roger Federer.

Serbia's Novak Djokovic has moved a step closer to winning the only ATP World Tour Masters 1000 event that has eluded him in his career, rallying to defeat Frenchman Adrian Mannarino 4-6, 6-2, 6-1 in the second round of the Western & Southern Open here.