SYDNEY, Jan 8 (Reuters) - 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 quarter-finals on Thursday to set up a last-four clash with Switzerland.

Mensik struggled with double faults in ‍the second set as Bergs won ‍6-2 7-6(4), before former ‌world number one Mertens beat Krejcikova 5-7 6-1 7-5 to ‍seal ​the tie.