09/11/2013 02:57 EDT | Updated 11/10/2013 05:12 EST

Hercog upsets Flipkens at Challenge Bell; Canadian Dubois loses in first round

QUEBEC - Polona Hercog upset top-seed Kirsten Flipkens 6-3, 6-1 on Tuesday in the first round of the Challenge Bell tennis tournament.

Stephanie Dubois of Laval, Que., lost to No. 4 Bethanie Mattek-Sands 6-3, 6-4. Seventh-ranked Lauren Davis had the last word in a 6-7(5), 6-3, 6-2 victory over Camila Giorgi after over two hours and forty minutes of play.

No. 2 Kristina Mladenovic held off qualifier Melanie Oudin 7-6(5), 5-7, 6-2.

Also, No. 3 Lucie Safarova defeated Anna Tatishvili, 6-3, 6-2. Also, Sesil Karatantcheva topped fellow qualifier Amra Sadikovic 6-3, 6-4. A second qualifier will be moving on to the second round as Julie Coin won her match against Michelle Larcher de Brito 7-6(5), 7-5.