Second seed Fabiano Caruana was back in action after isolating following the withdrawal of his second-round opponent Susanto Megaranto of Indonesia during their match because of a positive COVID-19 test.

The American, who lost his challenge for Carlsen’s title on a tiebreak in 2018, drew his opening game against Kazakhstan’s 66th seed Rinat Jumabayev.

Meanwhile Uzbekistan’s 173rd Jahongir Vakhidov, having beaten the US ninth seed Leinier Dominguez, took a 1-0 lead over 73rd-ranked home player Pavel Ponkratov.

And Vakhidov’s 15-year-old countryman Javokhir Sindarov, who produced the shock of the second round by beating France’s eighth seed Alireza Firouzja on a tiebreak, held his own with an opening draw against Peru’s 57^th seed Jorge Cori.

Another upset may be in prospect after sixth seed Shakhriyar Mamedyarov of Azerbaijan put himself under pressure by losing his opening game against Armenia’s Haik Martirosyan, seeded 59.

One of Russia’s main hopes, fifth-seeded Alexander Grischuk, took a 1-0 lead over Argentina’s Alan Pichot.

Another strong Russian challenger, 10^th seed Sergey Karjakin, whose challenge for Carlsen's world title in 2016 failed on a tiebreak after they had finished at 6-6, won his opening game against fellow countryman Grigoriy Oparin.

Fourth seed Anish Giri of The Netherlands drew his opening third-round game against Uzbekistan’s Nodirbek Abdusattorov.

In the inaugural International Chess Federation (FIDE) Women’s World Cup, which is running in parallel with the open FIDE World Cup, 17-year-old Carissa Yip of the United States took a 1-0 third-round lead over Georgia’s fifth-seeded Nana Dzagnidze.

There was another surprise result as home player Valentina Gunina, seeded 27th, won her opening game against Dutch player Harika Dronavalli, seeded sixth.