Indian Grandmaster P Harikrishna slipped to fifth spot from a share of lead after a win-less day at the Saint Louis Rapid and Blitz online chess tournament, where he lost to Ian Nepomniachtchi and world number one Magnus Carlsen.
Harikrishna, who shared the lead with Lev Aronian after three rounds, lost the fourth round of the Rapid event to Nepomniachtchi, then drew with Armenian Aronian before losing the sixth to Carlsen.
Meanwhile, Carlsen bounced back after a below-par opening day to record three victories and jumped to sole lead with nine points.
The Norwegian outplayed India No.2 in 31 moves to wrap up a succesful day on which he also defeated Aronian and Leinier Dominiguez (USA).
Harikrishna held Aronian to a draw in 58 moves after a 45-move defeat at the hands of the Russian.
Harikrishna now faces Americans Jeffery Xiong, Hikaru Nakamura and Wesley So in the last three rounds.
In each rapid game, a win is worth two points while a draw fetches a player one 1 point.
The ten players are competing for a USD 250,000 prize fund in nine rapid games and eighteen blitz games over five days of play.
The tournament hosted by US-based St Louis Chess Club concludes on September 19.