Anastasia Rodionova caused the biggest upset at Wimbledon on a day of few surprises by ousting former US Open and French champion Svetlana Kuznetsova.
Kuznetsova, who has never been past the quarter-finals in eight attempts, saved a match point before going down 6-4 2-6 6-4.
Russian-born Rodionova, who was granted Australian citizenship last December, had come from 4-0 down in the final set to beat British No.1 Anne Keothavong in the first round.
The 28-year-old, who reached the third round at Roland Garros, will play China's ninth seed Li Na for a place in the last 16.
Third seed Caroline Wozniacki produced a performance fit for the Queen even though Her Majesty was not there to see it.
The Monte Carlo-based former Wimbledon junior champion was chosen to meet the Queen on her first visit to Wimbledon for 33 years only to discover that, by the time she got to follow Andy Murray onto Centre Court, the monarch had departed.
Undeterred, the 19-year-old Wozniacki treated the sparse crowd to another impressive display of her exciting potential as she gained a 6-4 6-3 victory over Wimbledon debutant Kai-Chen Chang, the world No.89 from Taipei.
"When you're out there on court, you just think about the yellow ball and that you want to win," she said. "I met Her Majesty earlier today, so that was a great honour."
"I thought I played well out there today. I felt like I was serving well, I was really pleased about that."
Wozniacki's third-round opponent will be 18-year-old Russian Anastasia Pavlyuchenkova, who beat Italian Roberta Vinci 6-2 7-6 but has an unenviable record against the Danish No.1.
"I have nothing to lose because I have already lost to her three times," Pavlyuchenkova said.
Defending champion Serena Williams breezed into the third round with a 6-0 6-1 rout of Russia's Anna Chakvetadze.
Eighteenth seed Aravane Rezai of France lost 5-7 6-3 6-3 to Klara Zakopalova, of the Czech Republic, while Barbora Zahlavova Strycova came from a set down to gain a 1-6 6-2 6-4 win over former world No.5 Daniela Hantuchova, who seems fated never to win Wimbledon.
Hantuchova, who is on her 10th visit to Wimbledon still striving to improve on a quarter-final appearance in 2002, hit 31 unforced errors, more than double her more conservative opponent.
Zahlavova Strycova, a 24-year-old from the Czech Republic has now matched her previous best record on her eighth visit to Wimbledon and next she plays former champion Maria Sharapova, who sent out a warning to her rivals with an impressive straight-sets win over Ioana Raluca Olaru of Romania.
The 16th-seeded Sharapova, who dropped just one game in her opener against Anastasia Pivovarova on Tuesday, faced a more testing examination on Thursday as she registered a 6-1 6-4 triumph over her spirited opponent.
Sharapova, who is returning to something like her old form after a long-term shoulder injury, believes she is a serious challenger for the Rosewater Dish.
"I'm here to contend and I'm here to win the tournament," she warned.
Poland's Agnieszka Radwanska maintained her fine record at Wimbledon by surging through to the third round in straight sets.
The 21-year-old seventh seed, who has reached the quarter-finals in each of the last two years, brushed aside Italian Alberta Brianti 6-2 6-0 on Court 18 to show her grass-court pedigree.
Elsewhere, 20-year-old left-hander Petra Kvitova, from the Czech Republic, put out 23rd seed Jie Zheng, of China, who