Nick Kyrgios came from a set down to beat world number one Daniil Medvedev at the Canadian Open, as Iga Swiatek won comfortably.

Women's world number one Swiatek comfortably reached the last 16 with a straight-set win over Ajla Tomljanovic.

The 21-year-old Pole, a two-time Grand Slam winner, won 6-1 6-2 and will play Brazil's Beatriz Haddad Maia next.

American great Serena Williams lost 6-2 6-4 to Swiss 12th seed Belinda Bencic in Toronto in her first match since the 23-time Grand Slam singles champion suggested she will retire from tennis.

Writing for Vogue, Williams said she will be "evolving away" from the sport after the US Open, which begins on 29 August.

Britons Cameron Norrie, Dan Evans and Jack Draper are also in action in the evening session.

Meanwhile, 22-time major winner Rafael Nadal confirmed on Wednesday that he will compete at next week's Cincinnati Open, having been forced to withdraw from the Canadian Open because of an abdominal injury.

Kyrgios continues fine form

Kyrgios recorded his eighth successive victory - but only his second against a reigning world number one - as he continued his excellent form in Montreal.

The Australian, who does not have a coach, reached his first Grand Slam final at Wimbledon in July, losing to top seed Novak Djokovic in four sets.

He ended a three-year title drought in Washington last week, claiming his first ATP title since 2019 at the Citi Open without losing a set - a result which saw him move into the world top 40.

"I feel like we know each other's games well. I'm not the type of player that goes into this match looking at rankings or anything like that, it's just who I'm playing and what kind of ball they're giving me," said Kyrgios, who has won 14 of his past 15 matches.

Kyrgios will meet Alex de Minaur for a place in the quarter-finals, after his compatriot beat Bulgarian 15th seed Grigor Dimitrov 7-6 (7-4) 7-5.

Spanish second seed Carlos Alcaraz missed a match point as he was stunned 6-7 (4-7) 7-6 (9-7) 6-3 by American world number 34 Tommy Paul, who set up a match against Croat Marin Cilic.

Norwegian fourth seed Casper Ruud overcame Slovak Alex Molcan 7-6 (7-3) 6-3 and will play Spaniard Roberto Bautista Agut, while Italy's seventh seed Jannik Sinner, who beat Frenchman Adrian Mannarino 2-6 6-4 6-2, faces Pablo Carreno Busta.

Swiatek cruises through

In Toronto, two-time Grand Slam champion Swiatek saw her remarkable 37-match winning streak ended at Wimbledon in July as she lost to Alize Cornet in the third round at the All England Club.

An 18-match streak on clay was then ended by Caroline Garcia in the quarter-final of her home tournament later that month.

But, having been granted a first-round bye, she needed little more than an hour to dismiss Australian Tomljanovic to claim a 19th successive hard court win, hitting 16 winners on her way to victory.

Haddad Maia later beat Canadian 13th seed Leylah Fernandez 7-6 (7-4) 6-1.

Meanwhile, American teenager Coco Gauff, seeded 10th, beat Wimbledon champion Elena Rybakina in three sets.

French Open finalist Gauff clinched her fifth match point to prevail 6-4 6-7 (8-10) 7-6 (7-3) and set up a last-16 meeting with Belarusian sixth seed Aryna Sabalenka, who won 6-4 6-3 against Spain's Sara Sorribes Tormo.

Estonian second seed Anett Kontaveit lost 6-4 6-4 to Swiss player Jil Teichmann but Greek third seed Maria Sakkari advanced, beating American Sloane Stephens 6-2 4-6 6-2.

However, Spanish fourth seed Paula Badosa, who was trailing 7-5 1-0 to Kazakh Yulia Putintseva, and Tunisian fifth seed Ons Jabeur, at the time 6-2 2-1 down to China's Qinwen Zheng 6-2 2-1, both retired because of injury.

Czech 14th seed Karolina Pliskova won 6-1 6-1 against American Amanda Anisimova, while Romanian 15th seed Simona Halep beat China's Zhang Shuai 6-4 6-2.