Defending champion Alize Cornet wasted no time in booking her place in round two of the WTA Katowice Open, but Magdalena Rybarikova and Karin Knapp were surprise casualties on Monday.
Frenchwoman Cornet, who defeated Camila Giorgi in the 2014 showpiece in Poland, needed just over an hour to see off the challenge of Kiki Bertens 6-1 6-3.
The second seed won 25 of 31 points on her first serve in a commanding display, the only blip in an otherwise flawless showing coming when she dropped serve when leading 2-1 in the second.
In contrast, Rybarikova was below her best as she slumped to a 6-2 6-3 loss to Alison van Uytvanck - a player placed 56 spots below her in the world rankings.
The Slovakian, seeded fourth, was broken on three occasions and failed to take the two break-point opportunities she created as she crashed out in a time of one hour and six minutes.
Knapp also failed to hit her usual standards as Vera Zvonareva defeated the sixth seed 7-5 6-4.
There were eight breaks of serve in total in a back-and-forth clash, but it was Russian Zvonareva who did enough to book a spot in round two.
Third seed Giorgi avoided the same fate, but needed three sets to overcome Denisa Allertova 7-5 4-6 6-4, while Polona Hercog was also taken the distance in her 6-0 3-6 6-2 win over Misaki Doi.