Bogdan-Daniel Deac scored a crucial win over former co-leader Ray Robson in round 4 of the Prague Masters to join Vincent Keymer in the lead of the standings. Keymer held David Navara to a draw in a 100-move game, while Wang Hao returned to a fifty-percent score by beating Haik Martirosyan. In the Challengers, three games ended decisively, with Benjamin Gledura winning to join Mateusz Bartel in the lead. | Photo: Anežka Kružíková