Belgium reached the semi-finals of the United Cup for the very first time as singles victories from Zizou Bergs and Elise Mertens clinched a 2-1 victory over Czechia on Thursday. 

Bergs and Mertens' wins rendered the mixed doubles contest a consolation for Czechia, who saw Linda Fruhvirtova and Dalibor Svrcina down Greet Minnen and Sander Gille. 

Belgium's victory set up a final four clash with Switzerland, who booked their place in the semi-finals after beating Argentina 2-1, led by the impressive Belinda Bencic. 

In the opening match of the quarter-final, Bergs' rapid start was key as he edged a second-set tie-break to confirm a 6-2 7-6 (7-4) triumph over world number 18 Jakub Mensik. 

That set the stage for Mertens to seal Belgium's progression, which she was able to do despite having to come from a set down before beating Barbora Krejcikova 5-7 6-1 7-5.

Minnen and Gille had the chance to make it a clean sweep for Belgium, but they were on the wrong end of a three-set thriller against Fruhvirtova and Svrcina to close out the day.

The Czech duo were forced to produce a stirring comeback of their own after a one-hour and eight-minute opening set, going on to win 6-7 (13-15) 6-3 10-3 in an epic encounter. 

Our first semifinalists in Sydney!

BELGIUM pic.twitter.com/er8BlqtA4P

— United Cup (@UnitedCupTennis) January 8, 2026

Data Debrief: Bergs goes back-to-back

After earning the biggest win of his career against Felix Auger-Aliassime in the group stages, Bergs produced another equally impressive display against Mensik here. 

The Belgian arrived at the United Cup with a record of 2-16 against top 20 opponents, but has now won back-to-back matches against such players. 

Indeed, since the event's inauguration in 2023, world number 42 Bergs is now the lowest-ranked player – and the first outside the top 20 – to claim multiple ATP or WTA top 20 wins at a single edition of the United Cup.