Fifth seed Denis Istomin needed just 79 minutes to see off Paul-Henri Mathieu at the Estoril Open in Portugal.
Istomin beat returning Frenchman Mathieu 7-5 6-1 to book his place in the second round.
The Uzbek was joined in round two by Dutch sixth seed Robin Haase, who beat Simone Bolelli of Italy 6-3 6-2, and another Italian, Paolo Lorenzo, who beat Frenchman Edouard Roger-Vasselin 3-6 7-6 (7/2) 6-4.
In the women's event, Italian top seed Roberta Vinci recovered from a nightmare second set to beat Russian wild card 6-1 1-6 6-4, while seventh seed Nadia Petrova brushed aside Portugal's Barbara Luz 6-0 6-1.
American Vania King beat Johanna Larsson of Sweden 6-7 (6/8) 6-3 6-0, and there were also wins for Spanish pair Carla Suarez Navarro and Silvia Soler-Espinosa over Olga Govortsova and Sorana Cirstea respectively.
