Number one seed Agnieszka Radwanska has failed to reach the semi-finals of the Korea Open following a 7-6(4) 2-6 2-6 defeat to Varvara Lepchenko.
The Polish pro was the first to lose serve in the opening set, but she bounced back instantly to break Lepchenko and put proceedings level on 2-2.
Two double breaks from both players resulted in the opening set being decided with a tie-break, which Radwanska edged 7-4.
The momentum appeared to be with Radwanska as she broke her opponent at the first time of asking, but Lepchenko launched a comeback by breaking the top seed three times to draw level on sets.
The third and final set played out almost identically to the second as Lepchenko fought back once again after losing her opening service game to win the match.
