Switzerland's Stefanie Voegele upset Barbora Zahlavova Strycova to reach the second-round of the Generali Ladies in Linz.
Voegele, a player 37 places below the sixth seed in the WTA rankings, wrapped up a 7-6 (7-4) 7-5 victory in two hours and 11 minutes.
The 24-year-old Swiss player and will play Slovakian Anna Schmiedlova in the next round after she beat Germany's Annika Beck 7-6 (8-6) 6-4.
Eighth seed Caroline Garcia was also knocked out after getting off to a stuttering start against New Zealander Marina Erakovic.
The Frenchwoman lost the first set 6-2 before levelling the match by claiming the second 6-4 to force a decider.
World No 87 Erakovic, ranked 53 places below Garcia, regrouped to win the third set and the match 6-2 4-6 6-4.
The 26-year-old Kiwi has won four of their five encounters to date and will now meet either Katerina Siniakova or Klara Koukalova of the Czech Republic in the second round.