Top-ranked and defending champion Dinara Safina has been knocked out in the second round of the Toray Pan Pacific Open by Taiwanese qualifier Chang Kai-chen.

Chang, ranked 132nd in the world, produced a 7-6 (5), 4-6, 7-5 win over her Russian rival to advance to the third round of the $2 million tournament.

Safina, who had a first-round bye, was leading Chang 5-4 in the third set when she double faulted to give up a break.

Chang held and then converted on her third match point on Safina’s forehand error.

Safina’s status as the world’s top-ranked player has been under scrutiny and a third-round loss to 72nd-ranked Petra Kvitova of the Czech Republic at the U.S. Open did little to ease that.

More In: Tennis | Sport