Raducanu, who is ranked 23rd in the world, achieved the second WTA tour-level win of her careerBritain'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, ranked 14th in the world, 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.
Raducanu enjoying home comforts in Romania
In the country where her father Ian was born, and where her grandmother stills lives, Raducanu has started to look at home in what is still only her fourth WTA tournament.
Despite having already won a Grand Slam and reached the fourth round at Wimbledon, earning regular victories at tour-level events is the next important stage of the British number one's development.
No fans have been allowed in the stadium to watch the matches because of rising coronavirus rates, but Raducanu says she has received plenty of warm support on the streets of Cluj-Napoca.
After a gritty win against Slovenia's Polona Hercog on Tuesday, that backing has perhaps helped, with the Briton looking relaxed and exuding confidence on her way to convincingly beating the 106th-ranked Bogdan.
"It is definitely taking me some time to find my feet still, I'm taking some learning from every match I play," said Raducanu.
"I'm not the finished product yet."
There were odd moments of concern, however, starting when Raducanu faced three break points in the opening game.
A trio of first serves saved them and Raducanu broke immediately in the next game, allowing her to take control of the first set.
Another early break put her in command of the second set, although any thoughts of completing a straightforward success were dashed by Bogdan breaking back for 2-2.
A third game in a row edged the Romanian ahead, only for Raducanu to respond maturely again.
Winning the next three - including a 12-minute game to break again for 4-3 - was another example of her ability to problem solve and the teenager clinically ended the contest in impressive fashion.
Norrie's ATP Finals bid hampered - but not over
Norrie did not drop a point on serve in the first set, before Auger-Aliassime fought backNorrie, 26, became the leading British men's player for the first time in his career after winning the Indian Wells title - one of the ATP Tour's biggest tournaments behind the four Grand Slams - last month.
Landing the prestigious prize has helped him rise into the world's top 15 and continued a remarkable breakthrough year where he has ranked among the leading players.
But the left-hander's bid to qualify for the season-ending ATP Tour Finals, which take place in Turin next month after leaving London, have been hampered by Auger-Aliassime's gutsy fightback.
A defeat looked unlikely for Norrie as his intensity and precision overwhelmed his opponent, who made a high number of unforced errors in the opening set.
But the Canadian world number 12 improved and, after saving the match points when Norrie became tight in the second-set tie-break, took command of the decider.
Defeat does not rule Norrie out of the tight race to Turin, though.
He trails Norway's Casper Ruud, Poland's Hubert Hurkacz and Italy's Jannik Sinner with two spots still remaining, but next week's Paris Masters offers increased qualification points.
