Sakkari, a semi-finalist at this tournament last year before losing to the eventual champion Emma Raducanu of Britain, was eliminated in the second-round by China’s Wang Xiyu.

Wang, ranked number 75 in the world, lost the first set 6-3 after a steady set from Sakkari, but the Chinese player claimed set two after posting more winners than her opponent in the set and breaking her serve to take it 7-5.

In a tight third set, Wang claimed the crucial break in the 12^th game, taking it 7-5 to complete the shock triumph.

Williams, who is playing in her final tournament, was made to work hard against Anett Kontaveit of Estonia. 

The six-time US Open champion took the first set 7-6 before Kontaveit hit back in the second with a 6-2 win.

However, Williams' experience helped the American super star to get the third and deciding set 6-2. 

She will now face Ajla Tomljanović of Australia in the next round.

Tomljanović meanwhile had beaten Russian Evgeniya Rodina 1-6, 6-2, 7-5 to reach the third round. 

Canadian Bianca Andreescu had a routine 6-2, 6-4 win over Haddad Maia of Brazil.

In another upset, 14th seed Leylah Annie Fernandez of Canada exited the tournament after going down to Ludmilla Samsonova of Russia 3-6, 6-7.

Elsewhere in the women’s singles draw, 12th seed Coco Gauff of the United States beat Romania’s Elena Gabriela Ruse 6-2, 7-6.

Gauff’s compatriot Madison Keys, the 20^th seed, also progressed through a tough battle against Italy’s Camila Giorgi.

A match lasting just under two-and-a-half hours went the distance, with the 2017 US Open finalist prevailing 6-4, 5-7, 7-6.

Fifth seed Ons Jabeur of Tunisia, runner-up in the women’s singles final at Wimbledon, was also a victor over American number 144 Elizabeth Mandlik, winning 7-5, 6-2.

In the men’s draw, 2012 US Open champion Sir Andy Murray of Britain recovered from a set down to overcome American Emilio Nava, world number 203, in four sets.

Nava claimed an 84-minute opening set 7-5, before Sir Andy showed all his experience in hot conditions on Arthur Ashe Stadium to battle back and win the next three sets 6-3, 6-1, 6-0, to complete victory in exactly three hours.

Later, defending champion Daniil Medvedev recorded a straight sets 6-2, 7-5, 6-3 win over Arthur Rinderknech of France to qualify for the third round. 

Britain's Jack Draper had a memorable win over sixth seed Felix Auger-Aliassime of Canada. 

Draper wrapped the match with three 6-4 wins over the Canadian.

Karen Khachanov of Russia was stretched against Thiago Monteiro of Brazil in the second round. 

The 17th seed prevailed 6-3, 6-3, 5-7, 6-4.

Elsewhere in the men’s draw, 2021 Wimbledon runner-up Matteo Berrettini of Italy, the 13^th seed, came from a set down to defeat world number 119 Hugo Grenier of France 2-6, 6-1, 7-6, 7-6 in just under three-and-a-half hours.

The 12^th seed Pablo Carreno-Busta of Spain also came from a set behind to earn victory, defeating Alexander Bublik of Kazakhstan 4-6, 6-4, 6-3, 7-6.