Defending champ Hsieh out of Malaysian Open

The Taiwanese's defeat, coupled with seed number one Caroline Wozniacki's first-round loss on Wednesday, means no defending champion or top seed has ever won the Malaysian Open.

Asked about this "tournament jinx", second seed Hsieh just laughed and said: "It's a new feeling for me because it's the first time I'm defending a title. I tried my best to retain the title and hold on to my ranking points."

The 23rd-ranked player said she would return in 2013 "for sure".

"I don't have a lot of pressure here like some other players. I'm here to enjoy Kuala Lumpur," she said. "Bethanie was once a top 30 player so she knows what's it all about. My mental strength was not so good today."

Mattek-Sands -- who is known as the Lady Gaga of tennis after attending the 2011 pre-Wimbledon party in a dress made of tennis balls -- already staged a surprise win Thursday when she crushed Duan Ying-Ying of China in two sets.

Mattek-Sands will now meet world number 29 and third seed Anastasia Pavlyuchenkova, who brushed aside Australian youngster Ashleigh Barty 6-2, 6-0 in just an hour.

Meanwhile, Japan's Ayumi Morita edged closer to winning her first ever WTA title after beating Luksika Kumkhum of Thailand 6-7 (7-9), 6-4, 6-1.

"I'm very happy to be in my fourth career semi-finals. I hope to continue doing my best and try to go further this time," the fourth seed said.

Morita, who ranks 55 in the world and has played in the Malaysian Open since the inaugural event in 2011, will meet 127th-ranked Karolina Pliskova of the Czech Republic in Saturday's semi-final.

Pliskova eliminated Austrian Patricia Mayr-Achleitner 7-5, 6-1 to set-up the meeting with Morita.