In the women's event, top-seeded Marion Bartoli also exited the tournament. After a disastrous start in her first-round match, the Frenchwoman fought back against Peng Shuai to win the second set before losing the match 6-0, 1-6, 6-4.
Third-seeded Anastasia Pavlyuchenkova of Russia went through with a 6-4, 6-4 victory over Israel's Shahar Peer.
Results on the second day of the WTA/ATP Portugal Open on Tuesday (x denotes seeding):
Women
First round
Galina Voskoboeva (KAZ) bt Sofia Arvidsson (SWE) 6-3, 6-4
Monica Niculescu (ROM) bt Tamira Paszek (AUT) 6-1, 6-3
Peng Shuai (CHN) bt Marion Bartoli (FRA x1) 6-0, 1-6, 6-4
Romina Oprandi (SUI) bt Kiki Bertens (NED) 6-3, 6-3
Kaia Kanepi (EST) bt Kristina Mladenovic (FRA) 6-4, 6-3
Anastasia Pavlyuchenkova (RUS x3) bt Shahar Peer (ISR) 6-4, 6-4
Estrella Cabeza Candela (ESP) bt Aravane Rezai (FRA) 5-7, 6-1, 6-3
Francesca Schiavone (ITA) bt Lourdes Dominguez Lino (ESP) 6-2, 4-6, 6-3
Monica Puig (PUR) bt Julia Goerges (GER x8) 7-6 (7/3), 6-2
Ursula Radwanska (POL) bt Dominika Cibulkova (SVK x2) 2-6, 6-4, 6-4
Men
First round
Alejandro Falla (COL) bt Andrey Kuznetsov (RUS) 7-5, 6-4
Albert Ramos (ESP) bt Carlos Berlocq (ARG) 7-6 (7/4), 2-6, 6-3
Victor Hanescu (ROM) bt Rui Machado (POR) 6-4, 6-4
Paolo Lorenzi (ITA) bt Niels Desein (BEL) 6-3, 4-6, 6-2
Robin Haase (NED) bt Pablo Andujar (ESP) 4-6, 6-2, 6-3
Tommy Robredo (ESP x8) bt Daniel Gimeno-Traver (ESP) 2-6, 7-5, 6-3
Gastao Elias (POR) bt Horacio Zeballos (ARG x7) 6-3, 6-4