World number one Iga Swiatek powered her way past German qualifier Eva Lys as she opened her campaign at the Stuttgart WTA tournament with an impressive second round victory on Wednesday.

Lys, ranked 342 in the world, went down fighting, but had few answers as Poland's Swiatek used her experience to grind out a 6-1, 6-1 victory on clay indoors.

The 20-year-old Swiatek was given a first-round bye in Stuttgart, where she is the favourite.

She has won her three previous tournaments this year in Miami, Indian Wells and Doha.

Earlier Karolina Pliskova came out on top in the battle of Czech Republic aces with a 6-4, 4-6, 7-6 (7/5) victory over compatriot Petra Kvitova in their first round tie.

In the round of 32, Pliskova will face Liudmila Samsonova after the Russian whitewashed French qualifier Chloe Paquet 6-0, 6-0 in the first round.