Second seeded former world junior champion Abhijeet Gupta was shocked by Arkadij Rotstein on a day that saw as many as six players emerging as joint leaders with four points apiece.
With four rounds still to go, Abhijeet slipped behind in the title race and will now need to do a lot of hard work in the remaining games to stage a comeback. It was from a position of strength that the Indian was outdone by Rotstein.
The other two Indians in the fray had good results as both International Masters Sahaj Grover and Ashwin Jayaram registered emphatic victories. While Grover defeated Woman Grandmaster Olga Stjazhkina of Russia, Jayaram had it easy against Christian Hess of Germany.
At the top of the tables, defending champion Illya Nyzhnyk played out a draw with overnight co-leader Dejan Bojkov of Bulgaria after surviving some anxious moments.
Mark Bluvshtein of Canada, Daan Brandenburg of Holland, Peter Prohaszka of Hungary and Rotestein joined Bojkov and Nyzhnyk as joint leaders.
Khosla is in the next group of 3.5 pointers while Abhijeet, Grover and Jayaram are all on three points.
At one point, the Indian had less than three minutes to make 20 moves but in the end all was well as Chiel could not find the best defense.
Abhijeet almost outplayed Rotstein from the white side of a Queen pawn game. The German was saddled with a very passive position and gave Abhijeet a huge advantage on space count and better placed pieces.
However, in the first time control, Abhijeet blundered and fell in to a simple tactical sequence that spelt disaster for him.
Grover faced the Petroff defense from Olga who played black. The middle game gave the Indian better prospects that he correctly calculated to lend in a better ending. Olga was sight of losing a handful of pawns when she called it a day.
Ashwin Jayaram is back on a track after his third victory in the tournament. The Indian won with black against Hess to set up a clash with Abhijeet Gupta in the next round.
Important and Indian Results round 5 (Indians unless specified):
Dejan Bojkov (Bul, 4) drew with Illya Nyzhnyk (Ukr, 4); Abhijeet Gupta (3) lost to Arkadij Rotstein (Ger, 4); Peter Prohaszka (Hun, 4) beat Sipke Ernst (Ned, 3); Mark Bluvshtein (Can, 4) beat Robin Van Kampen (Ned, 3); Davit Lobzhanidze (Geo, 3.5) drew with Zaven Andriasian (Arm, 3.5); Daan Brandenburg (Ned, 4) beat Jan Werle (Ned, 3); Friso Nijboer (Ned, 3.5) beat Roeland Pruijssers (Ned, 3); Shiven Khosla (3.5) beat Van O Olga Stjazhkina Oosterom Chiel (Ned, 2.5); Sahaj Grover (3) beat Olga Stjazhkina (Rus, 2); Chiristian Hess (Ger, 2) lost to Ashwin Jayaram (3).