Japanese star Ito, who won last week’s WTT Contender tournament, continued her undefeated run in the Middle East hub after beating Adriana Diaz of Puerto Rico 11-6, 9-11, 11-8, 11-8 at the Lusail Multipurpose Hall.

In an all South Korean affair Jihee Jeon came from a game down to defeat compatriot Yubin Shin 7-11, 11-7, 11-7, 11-5.

The remaining women’s singles quarter-finals both went the distance with Elizabeta Samara of Romania, who defeated third seed Kasumi Ishikawa yesterday, coming out on top 15-13, 7-11, 6-11, 11-8, 14-12 in a thrilling tussle with South Korea’s Hayeong Kim.

Tianwei Feng of Singapore also prevailed in a marathon contest 12-10, 12-14, 11-5, 7-11, 11-6 against Japan’s Hina Hiyata.

In the men’s singles draw, top seed Harimoto progressed comfortably through his quarter-final beating Youngsik Jeoung 11-7, 11-8, 11-9.

Third seed Yun-Ju Lin of Taiwan crashed out as he was beaten in straight games by Ruwen Filus of Germany 11-3, 13-11, 11-9.

Dimitrij Ovtcharov of Germany kept his quest for back-to-back WTT Middle East hub tournament wins intact, but had to battle back from two games down against Sweden’s Anton Kallberg, triumphing 8-11, 10-12, 15-13, 12-10, 11-9.

The remaining quarter-final also went the distance with Darko Jorgic of Slovenia coming out on top in a marathon final game, as he beat Sweden’s Kristian Karlsson 7-11, 11-4, 5-11, 11-8, 17-15.