15:05 CET - And that's it for today! Make sure you tune back in for tomorrow's Tennis Tracker as we cover the remaining quarter-final at the United Cup, and all the action in Brisbane, Auckland and Hong Kong.
14:59 CET - Sixth seed Mirra Andreeva has battled through in Brisbane, with the 18-year-old rallying from a set down to outlast Linda Noskova 5-7, 6-4, 7-5.
13:23 CET - We have had another big upset in Brisbane with women's second seed Amanda Anisimova being beaten by Marta Kostyuk 6-4, 6-3 to exit the tournament before the quarter-final stage.
16th seed Kostyuk will take on the winner of Mirra Andreeva and Linda Noskova in the last eight.
12:29 CET - Belgium have sealed their spot in the United Cup semi-finals after Elise Mertens' 5-7, 6-1, 7-5 triumph over Barbora Krejcikova gave them an unassailable 2-0 lead against Czechia.
Meanwhile, in Brisbane, fourth seed Jessica Pegula has survived a scare, coming from a set down to defeat Dayana Yastremska 5-7, 6-2, 6-3.
11:41 CET - Grigor Dimitrov has been dumped out in Brisbane, with the Bulgarian losing 7-6(1), 6-3 to Belgium's Raphael Collignon.
10:58 CET - Michael Mmoh is through to the last eight in Hong Kong after a mightily impressive 7-6(2), 7-6(4) triumph over fourth seed Karen Khachanov.
09:33 CET - Belgium have taken the lead in their United Cup quarter-final tie with Czechia after Zizou Bergs proved too strong for Jakub Mensik in a 6-2, 7-6(4) victory.
Elsewhere, fifth seed Madison Keys has progressed in Brisbane thanks to a thrilling 6-7(5), 7-6(5), 7-6(4) win over Diana Shnaider in three hours.
08:50 CET - Giovanni Mpetshi Perricard has come from a set down to progress in Brisbane, with the big-serving Frenchman outlasting home favourite Rinky Hijikata 4-6, 7-6(5), 7-6(4).
08:24 CET - Over in Hong Kong, Juncheng Shang and Marcos Giron have claimed impressive wins over Lorenzo Sonego and Alexandre Muller, respectively.
08:19 CET - Liudmila Samsonova is the latest woman through in Brisbane, with the 10th seed beating compatriot Aliaksandra Sasnovich in straight sets, 6-4, 6-4.
Meanwhile, in Auckland, top seed Elina Svitolina is through to the quarter-finals after a hard-fought 7-5, 6-4 victory over Katie Boulter.
07:40 CET - Good morning and welcome to our coverage of Thursday's tennis!
There are several notable results to catch you up on overnight, with women's top seed Aryna Sabalenka beating Sorana Cirstea 6-3, 6-3 in Brisbane and Elena Rybakina proving too strong for Paula Badosa in a 6-3, 6-2 triumph.
On the men's side of the tournament, Aleksandar Kovacevic and Brandon Nakashima have secured wins over Cameron Norrie and Quentin Halys, respectively, while Alexandra Eala and Magda Linette have progressed to the last eight in Auckland.
Check out the full schedule for tournaments in Brisbane (ATP), Brisbane (WTA), Auckland (WTA) and Hong Kong (ATP) via the links.