Chun began the day four shots behind Yang .
The leader began to falter on the back nine and by the 14th hole there was a three - way tie for the lead at six under par with world number three Lewis joining Chun and Yang .
Chun began the day four shots behind Yang , but the leader began to falter on the back nine and by the 14th hole there was a three - way tie for the lead at six under par with world number three Lewis joining Chun and Yang .