Former champion Maria Sharapova had her lack of match practice exposed by unseeded Argentine Gisela Dulko who claimed a nailbiting 6-2 3-6 6-4 victory in the second round at Wimbledon.
Sharapova, ranked 60 after suffering with a shoulder injury but given a special seeding of 24 here, had battered Dulko for the loss of three games in two previous meetings.
But the Russian struggled to find an answer to the world number 45's scurrying array of groundstrokes and changes of pace in the sunshine on Centre Court.
It is the second year in succession that Sharapova has crashed out in the second round, and the 22-year-old admitted she made too many mistakes.
'I had so many easy balls and I just made unforced errors from those,’ she said.
'I don't really know if that's because I haven't played. When I've had those situations before, those balls would be pieces of cake and today they weren't.'
Dulko, who will play in the third round at SW19 for only the second time in her career, revealed nerves almost got the better of her as the match drew to a conclusion.
'I was very nervous at the end,' she said.
'The last game took forever for me, so I was very relieved after that game.'
Serena Williams has warned her Wimbledon rivals there is more to come after demolishing Jarmila Groth on Court One today.
Last year's beaten finalist looked at ease as she recorded a routine 6-2 6-1 win over her Australian opponent.
The match lasted less than an hour against an opponent ranked 69th in the world, and second seed Williams was generally happy with her display, but believes she still has a lot left to come.
'I thought I played really well today,' said the American. 'I knew she was going to be tough so I had to be ready for the match.
'For me there's always room for improvement though. I still think I could have returned better, come to the net a little bit more.
'That's exciting to think I can do better.'
Seventh-seeded Russian Vera Zvonareva had few troubles in her second-round meeting with Frenchwoman Mathilde Johansson, claiming a 6-1 6-1 win in one hour and 15 minutes.
Victoria Azarenka of Belarus, the eighth seed, had an even easier time of things on Court Two, claiming a 6-0 6-0 success over Romanian Ioana Raluca Olaru.
Tenth seed Nadia Petrova also progressed with a 6-3 6-2 triumph over Shahar Peer, but there was disappointment for 16th seed Zheng Jie, who was beaten 6-3 7-5 by former world number five Daniela Hantuchova.
There were also victories for seeds Dominika Cibulkova, Virginie Razzano and Sorana Cirstea, although Anastasia Pavlyuchenkova was another second-round casualty, the 31st seed losing out to Italy's Roberta Vinci in straight sets.
