Grandmaster B Adhiban of India crashed through the defenses of ace Philipino Wesley So in the fourth round to occupy the joint third position in the Asian Individual Chess championship.
After a sedate start, Adhiban rose in contention for a place in the next World Cup with a masterly display that left his higher ranked opponent shocked.
The victory meant Adhiban is just half a point behind the leaders.
At the top of the tables, Grandmaster P Harikrishna played out a draw with Bu Xiangzhi of China to also inch to three points.
With 3.5 points, Xiangzhi was joined at the top by compatriot Yu Yangyi. The two Chinese will now clash against each other in the next round.
Another Indian in fray, Grandmaster Parimarjan Negi put aside his previous round loss against Xiangzhi and bounced back to beat Wen Yang of China.
Negi and Krishnan Sasikiran, who was held to a draw by Rinat Zumabayev of Kazakhstan, are also amongst those who have three points in their kitty.
The Indian challenge, however, suffered a serious setback in the women's section when top seed D Harika went down to Munguntuul Batkhuyag of Mongolia.
While the victory helped the Mongolian to maintain a clean slate with an all-win record thus far, Harika slipped way behind the rest on 2.5 points.
The other Indian girls had a mixed day. Eesha Karavade and Mary Ann Gomes played out a draw amongst themselves while Soumya Swaminathan finally found her winning touch at the expense of Homa Alavi of Iran.
Swathi Ghate, however, continued to struggle as she lost to Guliskhan Nakhbayeva of Kazakhstan.
Adhiban's transition to a queen pawn player is coming handy and his new found love gave him a dynamic position he was looking for against So who played black.
The middle game was quite intense and So sacrificed a piece for illusive counter play in the center. Digesting that well, Adhiban pocketed another rook for a minor piece and the rest was just too easy for the Chennai based player.
Negi came up with a sterling performance to down Wen Yang. The Sicilian Najdorf by the Chinese did not come good as Negi launched an early attack and even though black had his chances, the Indian handled the ensuing position better to romp home in just 36 moves.
Harikrishna played out an easy draw with white from a Slav defense with Xiangzhi while Sasikiran's attempt to complicate matters against Zumabayev did not bear fruits as the latter exchanged pieces to reach a drawn endgame.
Important and Indian results of round 4 (Indians unless stated):
P Harikrishna (3) drew with Bu Xiangzhi (CHN, 3.5); Krishnan Sasikiran (3) drew with Rinat Jumabayev (KAZ, 3); Yu Yangyi (CHN, 3.5) beat Amirreza Pourramezanali (IRI, 2.5); Parimarjan Negi (3) beat Wen Yang (CHN, 2.5); B Adhiban (3) beat Wesley So (PHI, 2); Megaranto Susanto (INA, 2.5) drew with Surya Shekhar Ganguly (2.5); Abhijit Kunte (2.5) drew with Zhou Weiqi (CHN, 2.5); Dao Thien Hai (VIE, 2.5) drew with G N Gopal (2.5); John Paul Gomez (PHI, 2) drew with Debashis Das (2); Alavi Sayed Javad (IRI, 2) drew with S P Sethuraman (2); Bakr Jwan (SYR, 1) lost to Vidit Gujrathi (2); M Shyam Sundar (2) beat Arabi Saeid (IRI, 1); Vaibhav Suri (1) beat Yang Ching Wei Austin (TPE, 0).
Munguntuul Batkhuyag (MGL, 4) beat D Harika (2.5); Huang Qian (CHN, 3) drew with Irine Kharisma Sukandar (INA, 2.5); Nafisa Muminova (UZB, 3) beat Minoo Asgarizadeh (IRI, 2); Mary Ann Gomes (2.5) drew with Eesha Karavade (2.5); Nguyen Thi Mai Hung (VIE, 2) lost to Pham Le Thao Nguyen (VIE, 3); Mitra Hejazipour (IRI, 1.5) lost to Padmini Rout (2.5); Swathi Ghate (1) lost to Guliskhan Nakhbayeva (KAZ, 2); Soumya Swaminathan (1.5) beat Homa Alavi (IRI, 1).