Defending champion Ratchanok Intanon of Thailand beat world number one Tai Tzu Ying of Chinese Taipei in a repeat of last year's final at the Badminton World Federation (BWF) Malaysia Masters.
This year, Intanon and Tai met in the quarter-final of the competition at the Axiata Arena in Kuala Lumpur.
Intanon was again victorious, defeating her opponent 21-13, 21-14 to progress to the semi-final.
“I’m not afraid of her style," Intanon said.
"We know each other, what our favourite shots are.
"I know her and she knows me.
"But it depends on who can control the shuttle on the day.
"I know that she is a strong player and has good skill, we have almost the same style.
"It was important that I stayed focused."
She will now play youth Olympic champion Goh Jin Wei of Malaysia, who beat China's He Bingjiao 21-15, 21-16 in her quarter-final.
The other semi-final will see Olympic champion Carolina Marin of Spain, who won against South Korea's Sung Ji Hyun 21-13, 21-13, take on India's Saina Newhal, who defeated Japan's Nozomi Okuhara 21-18, 23-21.
In the men's competition, Denmark's Viktor Axelsen continued his title defence by triumphing against Malaysia's Lee Zii Jia 21-12, 22-20.
He will now face Chen Long in the semi-final, with the Chinese player beating Indonesia's Anthony Sinisuka Ginting 21-11, 22-20.
Crowd favourite Daren Liew of Malaysia defeated China's Shi Yuqi 21-12, 16-21, 21-11 to set up a semi-final clash against South Korea's Son Wan Ho.
“If you’d asked me before the match if I could beat him, I wouldn’t have fancied my chances against a player who had just won the World Tour Finals,” said Liew.
“But like in the previous matches, I’m the underdog and there was no pressure.
"I just went out there to play my best and thought of nothing else.”
Son beat India's Kidambi Srikanth 21-23, 21-16, 21-17.