Mamallapuram (Chennai), Jul 31 (IANS): Favourites fumbled in the second round of the women's section at the 44th Chess Olympiad as former world champion Mariya Muzychuk of Ukraine suffered defeat against Turkey's Ekaterina Atalik while India's Koneru Humpy forced to split point against much lower rated Marisa Zuriel of Argentina, here on Saturday.

Besides these individual upsets, the Top-20 seeds remained unscathed. All the three Indian women teams won their matches and extended their winning run at the prestigious event.

Azerbaijan, Armenia and Romania were the teams in the Top-20 ranking which whitewashed their opponents with a 4-0 score. This event is a 11-round Swiss league one where four players are fielded for each round.

R Vaishali, Tania Sachdev and Bhakti Kulkarni's victories helped India A team to score a 3.5-0.5 victory against Argentina.

The Argentine Zuriel opted for the volatile Benko Gambit against Humpy who skipped the popular continuation without accepting the gambit. A blocked position with little headway had Humpy settling for a draw after 44 moves with each having a queen, a rook and opposite colour bishops with identical numbers of pawns.

Sachdev, who was stretched for more than 100 moves on Friday, scored a quick victory against Anapaola in a Grunfeld game which lasted 36 moves after her queen, rook and knight set up a checkmating net.

India B team defeated Latvia 3.5-0.5 with Vantika Agrawal, Soumya Swaminathan and Mary Ann Gomes emerging victorious and Padmini Rout conceding a draw to Nellija Maklakova.

India C team, on the other hand, beat Singapore with a 3-1 score with Eesha Karavade and PV Nandhidhaa scoring victories while Pratyusha Bodda and Vasnawala Vishwa being held to draws.

Nandhidhaa was involved in a Pirc Defence game against Emmanuelle Mei-En and crafted a neat victory with strongly placed pieces and an extra bishop. The game lasted 34 moves.