Petra Kvitova's preparations for the defence of her Wimbledon title suffered a setback when she was beaten by Russia's Ekaterina Makarova in the first round of the Eastbourne International on Tuesday.
The number two seed, who beat Maria Sharapova in the final of last year's Wimbledon, lost 7-5, 6-4 to Makarova who is ranked 48th in the world.
Kvitova had looked in good shape heading into the grasscourt season, having lost in the semi-finals of the French Open to eventual champion Sharapova.
Makarova is joined in the second round by number five seed Angelique Kerber of Germany who beat Russia's Elena Vesnina 3-6, 6-0, 7-5.
Wimbledon starts on Monday.
