Bergs upsets Mensik as Belgium beat Czech Republic

Zizou Bergs stunned world number 18 Jakub Mensik and Elise Mertens outplayed Barbora Krejcikova as Belgium beat the Czech Republic 2-0 in the United Cup quarterfinals on Thursday to set up a last-four clash with Switzerland.

Zizou sets the tone 💪

Belgium out to a 1–0 lead against Czechia 🇧🇪 pic.twitter.com/vQNW7wCZVl — United Cup (@UnitedCupTennis) January 8, 2026

Mensik struggled with double faults in the second set as Bergs won 6-2 7-6(4), before former world No 1 Mertens beat Krejcikova 5-7 6-1 7-5 to seal the tie.

Bergs, ranked 42nd in the world, landed four aces as he took the first set in 31 minutes, and kept his cool through a tense second-set tiebreak to clinch his second straight win over a top-20-ranked opponent, having beaten Canadian world No 5 Felix Auger-Aliassime in the group stage.

"You’re so close, you’re playing big points. I got tight, I go backwards, I play defensive. So it was a very big struggle in the end. I'm so happy for myself and the team," Bergs said.

Mertens wore down two-time Grand Slam winner Krejcikova who committed seven double faults in the third set.

"I felt like I had to play a little aggressive... I'm really happy I could turn it around. It was 1-0 for Belgium, so I could play freely, thanks to Zizou," Mertens said.

Australia face Poland on Friday for a place in Saturday's first semifinal against the United States.