Britain's Emma Raducanu produced a composed display to beat Romania's Ana Bogdan in straight sets and reach the Transylvania Open quarter-finals.
The US Open champion backed up her opening win in Cluj-Napoca - a first at tour level - with a 6-3 6-4 victory.
Third seed Raducanu, 18, will face 19-year-old Ukrainian Marta Kostyuk next.
Meanwhile, British men's number one Cameron Norrie spurned three match points in losing to Canadian sixth seed Felix Auger-Aliassime in Vienna.
Norrie was within touching distance of the quarter-finals, only for Auger-Aliassime to recover and eventually win 2-6 7-6 (8-6) 6-4.