MANILA, Philippines – Grandmaster Wesley So blew away a winning line and instead took a stinging setback to Chinese GM Yu Yangyi to turn in a disappointing 18th place finish in the 2015 Qatar Masters Open in Doha, Qatar Tuesday night.
So won a piece for two pawns and looked headed to finishing off Yu in their Nimzo-Indian Defense duel but missed the winning combination at endgame, allowing the latter to snatch the upset victory in 77 moves.
The loss came a day after So was held to a draw by another Chinese, lowly ranked International Master Lin Chen in 132 moves of a Slav.
That forgettable finish sent So tumble down to joint No. 18 with 5.5 points while the win enabled Yu to gain a share of first with top seed reigning world champion GM Magnus Carlsen of Norway with seven points.
Carlsen eventually crushed Yu, seeded only 11th with a 2736 rating, with a two-game sweep of their blitz playoff to crown himself champion of the nine-round event worth $27,000.
So, meanwhile, slid from No. 9 in the world to No. 10 with a live rating of 2773.2.