WIJK AAN ZEE, Netherlands — Grandmaster Wesley So bungled what looked like a winning line and allowed former world junior champion GM Emil Sutovsky of Israel to escape with a draw in the ninth round of the 72 nd Corus chess tournament at the De Morian Community Centre.

So vaulted to strong positional advantage with the white pieces and looked headed to another triumph against the time-pressured Sutovsky with a clear pawn advantage in a rook and knight ending.

But the16-year-old Filipino champion missed the right continuation despite his advantage on time and allowed the Baku, Azerbaijan-born Sutovsky champion to force a standoff in 42 moves of the Gruendfeld.

When the truce was reached, So has a rook, knight and four pawns against the rook, knight and three pawns of the 33-year-old Sutovsky.

Overall, So now has 5.5 points on two wins and seven draws with four rounds remaining.

So is only a full point behind solo leader GM Anish Giri of the Netherlands and half a point behind GMs Ni Hua of China an Erwin l’Ami of the Netherlands.