Vietnam's chess ace Le Quang Liem lost to Russian Alexander Khalifman in the fourth round of the Aeroflot Open 2012 Group A in Moscow on Saturday.
Playing white, the reigning champion Grandmaster Liem, ranked 29th globally with an elo of 2714, could not beat or even draw with Khalifman, elo 2632.
The defeat pushed the defending champion 20-year-old 35 positions to 51st with 2.5 points while 46-year-old Khalifman, who was Liem's instructor for two months in 2010, jumped 24 places to fourth with 3.5 points.
The 23-year-old Israeli Maxim Rodshtein is now leading Group A with 4 points, followed by Ukrainian GM Anton Korobov and Armenian GM Hrant Melkumyan, both with 4 points each.
The two-time Aeroflot champion Liem's hopes for a third-straight title have been all but dashed by the loss as he now sits in the fourth group of 22 players with 2.5 points each.
In the next round of the February 6-17 event, Liem will clash with the USA GM Ray Robson, elo 2595.