Former British number one Laura Robson has had her best win since wrist surgery two years ago.
The world number 465 beat Klara Koukalova, who is ranked 117, 6-2 6-3 in the first round of qualifying for the WTA clay court event in Stuttgart.
She returned from a 17-month lay-off in June but had a relapse and did not play until Indian Wells last month.
The 22-year-old will use her protected ranking of 58 to gain direct entry into the French Open main draw in May.