Johanna Konta made it through to the semi-finals of the Kremlin Cup after edging out Aliaksandra Sasnovich.
The British No 1, who had already beaten Elise Mertens and Daria Gavrilova to reach the last eight, continued her excellent late-season run in the Russian capital with a nervy 2-6 6-2 7-6 (7-2) victory over Sasnovich.
Konta, currently ranked world No 44, reached her first semi-final since June where she will play Daria Kasatkina after the sixth seed beat Anastasia Pavlyuchenkova 6-4 6-3.
Konta has been working with Frenchman Dimitri Zavialoff, long-time coach of Stan Wawrinka, a week after splitting from coach Michael Joyce following a disappointing first season together.
The early signs have looked positive for the 27-year-old after showing some of the form which helped her climb to as high as world No 4 in the WTA rankings last year.
Anastasija Sevastova reached the last four by beating Russian veteran Vera Zvonareva 4-6 7-5 6-3, and will next face Tunisian qualifier Ons Jabeur, who upset eighth-seeded Anett Kontaveit 7-5 6-1.
Nick Kyrgios withdrew from the men's tournament with an elbow injury, giving Mirza Basic a walkover to the quarter-finals, where he'll play Karen Khachanov.
"I'm going to choose to wrap up my season, head home and start the recovery," the Australian said. "See you all in 2019."
Cameron Norrie was narrowly beaten in the European Open quarter-finals by Diego Schwartzman.
The British No 2 lost in three tight sets 7-6 (7-1) 6-7 (3-7) 7-5 in two hours and 34 minutes.
Down a break in the deciding set, Norrie fought back from 4-2 down to lead 5-4 but Schwartzman got the break of serve back before closing out the match in Antwerp.
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