Samantha Stosur survived an early scare before winning her second round clash with American Christina McHale at the WTA's Madrid Open in Spain.
Stosur dropped the first set against teenager McHale before hitting back to win 2-6, 6-4, 6-0 in just under two hours on the blue clay.
She will meet Petra Cetkovska in the third round after the Czech enjoyed a comfortable straight sets win over Spaniard Lourdes Dominguez Lino, winning 6-4, 7-5 to advance.
Serena Williams marked her first European appearance of the season with victory on the Madrid Open's striking blue clay courts but it was not such good news for sister Venus, who crashed out.
Serena, who reached the third round the last time she played in Madrid in 2010, powered past last week's Budapest Grand Prix runner-up Elena Vesnina of Russia 6-3, 6-1.
The ninth seed delivered some powerful serves, hitting 14 aces to set up a meeting with another Russian, Anastasia Pavlyuchenkova, in the next round.
"I was feeling good," Williams told reporters.
"It's my first tournament in Europe this year and I just hope I can keep up the good form," added the American who has yet to lose in eight clay outings this season.
"I haven't noticed a difference between the blue and the red clay. I think it's the same, it's just you don't get as dirty," Williams said.
Venus entered Madrid on a wildcard as she started her third tournament after seven months out suffering with Sjogren's Syndrome, an auto-immune disease which causes fatigue and joint soreness.
The former world number one struggled past Romania's Simona Halep in three sets on Saturday, but crumpled against stronger opposition on Monday falling 6-4, 6-1 to 12th seed Angelique Kerber of Germany.
Kerber, 24, is in the midst of her breakout season with both her career titles coming in 2012.
China's Li Na, the eighth seed, joined Kerber in the last 16 with a straightforward victory over Spanish wildcard Silvia Soler-Espinosa 6-3, 6-1.
Holder Petra Kvitova started well as the third seed defeated New Zealander Marina Erakovic 6-2, 6-3.
Towering Czech Kvitova beat Victoria Azarenka in the final last year before going on to win the Wimbledon title.
The only seeded player to fall was number 15 Jelena Jankovic who went out to Spanish wildcard Carla Suarez 4-6, 7-6, 6-4.
Czech qualifier Andrea Hlavackova and compatriot Lucie Hradecka, Italian Sara Errani, Russia's Ekaterina Makarova, and Estonia's Kaia Kanepi also made it through to the second round.
ABC/ReutersTags: sport, tennis, spain First posted May 08, 2012 12:07:13