Promising Australian teenager Ashleigh Barty has made her first WTA quarter-final, advancing to the last eight of the rain-delayed Malaysian Open.

Barty, 16, was too good for Zarina Diyas, outlasting the qualifier 7-6 (7-3) 6-4.

She will now play world No.29 Anastasia Pavlyuchenkova in the quarterfinal of the low key event.

Regarded as one of the best local tennis players to come through in the past decade, Barty enjoyed a strong start to the year by reaching the Australian Open women’s doubles final with Casey Dellacqua.

Meanwhile second seed and defending champion Hsieh Su Wei of Taiwan overcame fatigue, leg cramps and two opponents Thursday to reach the last eight.

Hsieh, who ranks world No.23 and is hoping to become the first player to successfully defend a title here, started her day by beating Kurumi Nara of Japan 6-7 (5-7) 6-3 6-4 in a match held over from Wednesday.

She was leading 4-3 when the match was halted Wednesday due to rain. She needed another two hours to complete her first round match Thursday and was back on court three and a half hours later to face Zhang Shuai of China.

Hsieh, who needed two medical times against Nara, was energised by her break and romped past Zhang 6-3, 6-3 in 73 minutes.

The 27-year-old will now face wildcard entry Bethanie Mattek-Sands, who stormed into the quarterfinals when she crushed Duan Ying-Ying of China 6-1 6-4.

The colourful American, who also sports several tattoos, was one of five players to secure quarter-final berths so far.