American So, who is currently at number eight in the FIDE rankings, drew his second game today against European champion Alexey Sarana of Serbia, which meant he was eliminated from the open tournament.

In a match So needed to win, the contest was even throughout and with neither player unable to gain an advantage, a draw was declared.

His compatriot Caruana defeated fellow American Ray Robson in today’s second game, following an effective attack on his opponent’s black king, to gain victory.

The day’s other qualifiers in the open event included India’s Vidit Santosh Gujrathi, with a draw today against Etienne Bacrot of France and Nils Grandelius of Sweden, who drew today with Jaime Santos Latasa of Spain, enough to progress after wins the previous day.

The two other players in the open event to progress today were Indian Arjun Erigaisi, who beat Javokhir Sindarov of Uzbekistan after he made a mistake during a rook end game, and Ferenc Berkes of Hungary, whose draw with Ruslan Ponomariov of Ukraine today was enough to progress.

The big upset yesterday on day one of the fourth-round matches at the Baku Marriott Hotel Boulevard was world number one Magnus Carlsen of Norway losing to teenager Vincent Keymer of Germany.

Carlsen needed to win today’s game to stay in the tournament, and things got off to a bad start when he made an early error.

He was not punished and a better end game performance ensured he got the victory to force a tiebreak match tomorrow.

In a revealing interview after the match Carlsen said: “Since day one I was wondering what am I doing here, why am I spending all this time playing classical chess which I just find stressful and boring."

In the women’s tournament three players secured their progression to the next stage today.

Alexandra Goryachkina, the world number two female player on FIDE ratings, playing as a neutral, beat Georgia’s Nino Batsiashvili, with a dominant performance to advance.

An attacking display from Tan Zhongyi saw her get the win to defeat fellow Chinese player Zhu Jiner, while neutral athlete Polina Shuvalova took advantage of a blunder by Teodora Injac of Serbia to get the win needed to advance.

Among the drawn matches going to tiebreaks are reigning women’s world champion Ju Wenjun of China against Germany’s Elisabeth Paehtz, and the encounter between Ukrainian sisters Anna and Mariya Muzychuk.

Tiebreaks for round four matches that have yet to be won are due to take place tomorrow, with these required in ten matches in the open draw and five in the women’s.