Madrid - World No 1 Serena Williams eased into the third round of the Madrid Open with a 6-2, 7-5 win over Spain's Lourdes Dominguez Lino on Tuesday.
The American had struggled early on in her first-round match against Kazak qualifier Yulia Puntitseva, but began much brighter as she broke Dominguez Lino straight away to take command.
A momentary lapse in concentration at 5-1 saw Williams broken, but she responded immediately to break the Spaniard's serve once more to close out the set.
The second set started in a similar vein as Williams seized a 2-0 lead, but Dominguez Lino fought back bravely to level matters at 2-2 before the next seven games went with serve.
However, the World No 47 finally crumbled when serving to stay in the match at 5-6 as Williams broke to love to seal victory.
Earlier, 14th seed Marion Bartoli overcame a twisted ankle during the second set of her match against Spaniard Maria-Teresa Torro-Flor to progress 6-4, 2-6, 6-4.
Serbian Janko Tipsarevic became the first seed in the men's event to fall on Tuesday morning as he was beaten by clay court specialist Juan Monaco.
The Argentine took the first set in the tie-break 7-5 before coming through 6-3 in the second.
And world No 15 Stanislaw Wawrinka continued his fine form after winning the Portugal Open last week with a comfortable 6-4, 6-4 win over Romanian qualifier Marius Copil.Results from the fourth day of the ATP and
WTA Madrid Open on Tuesday (x denotes seeding):
Serena Williams (USA x1) bt Lourdes
Dominguez Lino (ESP) 6-2, 7-5
Marion Bartoli (FRA x14) bt Maria-Teresa
Torro-Flor (ESP) 6-4, 2-6, 6-4
Yaroslava Shvedova (KAZ) bt Kirsten
Flipkens (BEL) 6-2, 4-6, 6-4
Anabel Medina Garrigues (ESP) bt Madison
Keys (USA) 7-6(7/3), 6-3
Sabine Lisicki (GER) bt Dominika Cibulkova
(SVK x15) 7-6(7/4), 7-6(7/3)
Svetlana Kuznetsova (RUS) bt Nadia Petrova
(RUS x11) 7-6(7/2), 4-6, 6-4
Ana Ivanovic (SRB) bt Chanelle Scheepers
(RSA) 6-2, 6-2
Juan Monaco (ARG) bt Janko Tipsarevic (SRB
x9) 7-6 (7/5) 6-3
Benoit Paire (FRA) bt Joao Souza (BRA) 6-1,
Santiago Giraldo (COL) bt Martin Klizan
(SVK) 6-2, 6-4
Mikhail Youzhny (RUS) bt Fabio Fognini
(ITA) 7-6 (7/4), 2-6, 7-6(7/5)
Stanislas Wawrinka (SUI x15) bt Marius
Copil (ROM) 6-4, 6-4
Tommy Haas (GER x13) bt Andreas Seppi (ITA)
Victor Troicki (SRB) bt Marcel Granollers
(ESP) 7-5, 4-6, 6-2
Tommy Robredo (ESP) bt Marcos Baghdatis
(CYP) 6-4, 6-2
Grigor Dimitrov (BUL) bt Novak Djokovic
(SRB x1) 7-6 (8/6), 6-7(8/10), 6-3
Roger Federer (SUI x2) bt Radek Stepanek
(CZE) 6-3, 6-3
Andy Murray (GBR x3) bt Florian Mayer (GER)
Daniel Gimeno-Traver (ESP) bt Richard
Gasquet (FRA x8) 7-5, 3-6, 6-4
Gilles Simon (FRA x16) bt Jeremy Chardy
(FRA) 6-4, 7-6(7/5)
Fernando Verdasco (ESP) bt Milos Raonic
(CAN x12) 6-4, 2-6, 7-6 (9/7)
Pablo Andujar (ESP) bt John Isner (USA)