Japan's Naomi Osaka hits a return against Ukraine's Elina Svitolina during their women's singles match on day four of the 2016 Australian Open tennis tournament in Melbourne on January 21, 2016. AFP PHOTO / SAEED KHAN-- IMAGE RESTRICTED TO EDITORIAL USE - STRICTLY NO COMMERCIAL USE / AFP / SAEED KHAN (Photo credit should read SAEED KHAN/AFP/Getty Images)

The fourth major tournament of the year is finally underway as Olympic tennis in Tokyo returns after five years. Upsets have dominated the first few days of competition, with some familiar names cruising through to the third round.

Australia's gold medal hope and world number one Ash Barty lost in her first round match to Sara Sorribes Tormo of Spain. Barty, just weeks after winning her maiden Wimbledon title, looked uncharacteristically sloppy, making 27 unforced errors in the match.

Fellow Australians John Millman and Alya Tomljanovic both lost their second round matches, while James Duckworth is expected to face Russian Karen Kachanov on Tuesday.

Naomi Osaka has been denied the chance to win her first gold medal at her home Olympics after falling in the third round against Czech Marketa Vondrousova 6-1 6-4.

Osaka, who withdrew from both the French Open and Wimbledon earlier in the year, was a favourite coming into the games. The world number two lit the Olympic Cauldron at the Opening Ceremony ahead of her Olympic debut and cruised through the first round with a straight sets victory over Zheng Saisai. Vondrousova stunned the home town hero, with Osaka hitting 32 unforced errors in a match that lasted a little over an hour.

Elsewhere in the women's draw, other top seeds have continued to fall. Aryna Sabalenka lost to world number 50 Donna Vekic in three sets, while Petra Kvitova managed a one set lead before losing to Belgium's Alison Van Uytvanck in three.

Poland's young star Iga Switek was inconsolable after her second round loss to Paula Badosa. The 20-year-old, who won Roland Garros in 2020, lost the second set tiebreak 7-4 to give the Spaniard the win and broke down in tears on the court after the match. Swiatek still remains in the mixed doubles with Lukasz Kubot.


In the men's singles, defending gold medalist Andy Murray withdrew from his first match against Canadian Felix Auger-Aliassme with a quad complaint, replaced with Australian Max Purcell, who defeated the young Canadian in straight sets before losing to Germany's Dominik Koepfer.

Novak Djokovic remains on his way to achieve a golden slam after winning the opening three major tournaments of the year. The world number one has cruised into the third round, defeating Hugo Dellien and Jan-Lennard Struff in straight sets.

Elsewhere, Stefanos Tsitsipas has made his way into the third round after defeating American Frances Tiafoe, fellow seeds Alexander Zverev and Daniil Medvedev will join the Greek in round 3. Hometown prospect Kei Nishikori upset world number seven Andrey Rublev in the first round and will have to contend with an incoming tropical storm to take the court against American Marcos Giron on Tuesday.

Australia still remains in contention for a medal, with Ash Barty and Storm Sanders making it through to the third round in the women's doubles along with Sam Stosur and Ellen Perez, while both men's doubles teams lost in the first round. Ash Barty will be kept busy, partnering John Peers in the mixed doubles which features just 16 teams.