India's Grandmaster Rameshbabu Praggnanandhaa defeated overnight sole leader Nodirbek Abdusattarov of Uzbekistan to stake his claim for the top honours at the Prague Masters chess tournament in Prague.

Winning with the black pieces, Praggnanandhaa came within striking distance of the sole leader in the 10-player round-robin event with three rounds remaining.

Things worked out even better for Praggnanandhaa as the second-placed Parham Maghsoodloo of Iran went down to Nguyen Thai Dai Van of the Czech Republic.

As a result, Abdusattarov continued to rule the roost with four points and he is now followed by Praggnanandhaa, Richard Rapport of Romania and Maghsoodloo who all have 3.5 points apiece.

Praggnanandhaa was at the top of his game without giving anything to his opponent. The Ruy Lopez by white met with some deft manoeuvres and was shelved as Praggnanandhaa made consistent progress on all sides of the board.

As the game progressed, Abdusattrov found things to be difficult and eventually had to cave in.

Gukesh Dommaraju had a hard day as he went down to tail-ender Mateusz Bartel. With his white pieces, Gukesh was expected to score but it was one of those days when nothing worked to perfection.

Vidit Gujrathi was up against another shocker as he went down to Vincent Keymer of Germany. The Indian was the favourite in this encounter but could not make things work in his favour.

Results round 6 (Indians unless specified):

Nodirbek Abdusattarrov (Uzb, 4) lost to  R Praggnanandhaa (3.5); D Gukesh (2.5) lost to Mateusz Bartel (Pol, 2); Vidit Gujrathi (2) lost to Vincent Keymer (Ger, 3); Nguyen Thai Van Dan (cze, 3) beat Parham Maghsoodloo (Iri, 3.5); David Navara (Cze, 3) drew with Richard Rapport (Rou, 3.5).