Internationaux de Strasbourg sixth seed Dayana Yastremska cruised past Pauline Parmentier to set up a second-round tie with Samantha Stosur.
Yastremska, who has struggled with illness and injury since winning the Thailand Open earlier in the season, but showed no signs of fatigue.
The 19 year-old made light work of Parmentier - a former Strasbourg semi-finalist - in the first set, though the Frenchwoman rallied in the second before Yastremska prevailed on her third match point.
Next up will be Stosur, who the Ukrainian defeated in straight sets at this year's Australian Open, after the 2011 US Open champion defeated Jessica Pegula 6-3 6-1.
Top seed Ashleigh Barty starts her tournament against Daria Gavrilova.
Elsewhere, there were surprise defeats for eighth seed Zhang Shuai, who lost 6-4 6-1 to Astra Sharma, and fifth seed Sofia Kenin, beaten in straight sets by Chloe Paquet.
Rain prevented play in all but one match at the Nuremberg Cup, with Mona Barthel overcoming Paula Ormaechea 6-3 3-6 6-2.