Indian Grandmaster Vidit Santhosh Gujrathi lost his seventh-round game to Jorden Van Foreest while world No.1 Magnus Carslen got the better of R Praggnanandhaa to claim the lead position in the prestigious Tata Steel Masters chess tournament in Wijk Aan Zee, The Netherlands.
Van Foreest introduced an interesting novelty on the white side of Nimzo-Indian Defence against one of the leaders, Gujrathi and an error by the Indian GM on move 36 proved costly as the Dutchman capitalised to post a win late on Saturday.
It was Gujrathi's first defeat in the tournament and the Indian slipped to joint third spot after being among the leaders at the conclusion of the sixth round.
Meanwhile, Carlsen won his second straight game to grab the lead.
The world champion beat debutant Praggnanandhaa with black pieces while neither of his close competitors managed to score a full point. His victory came in 34 moves and took his tally to 5 points.
Daniil Dubov forfeited his game against Anish Giri after the Russian GM refused to play with a face mask.
It was a request by the organisers after someone Dubov was in contact with tested positive for COVID-19.
Azerbaijan's Shakhriyar Mamedyarov is in second place, half a point behind Carlsen while Gujrathi is in joint third with three others -- Andrey Esipenko, Giri and Richard Rapport -- on four points.
In the Challengers event being played simultaneously, Indian GM Arjun Erigaisi drew with Rinat Jumabayev of Kazakhstan in round seven to take his tally to 6 points. He is ahead of the field by one point.
Fellow Indian Surya Shekhar Ganguly is joint fourth with four points after drawing with Volodar Murzin (Russia) in the seventh round.
Standings after Round 7: Masters: 1. Magnus Carlsen 5 points; 2. Shakhriyar Mamedyarov 4.5; 3-6. Vidit Gujrathi, Richard Rapport, Andrey Esipenko, Anish Giri 4; 7-9. Sergey Karjakin, Fabiano Caruana, Jorden Van Foreest 3.5; 10-11. Sam Shankland, Jan-Krzysztof Duda 3; 12-13. Daniil Dubov, R Praggnanandhaa 2.5; 14.Nils Grandelius 2.