NEW YORK, NY, USA - The youngest player in the Top 100 continued to be the biggest surprise package at the US Open on Friday, following up her second round stunner over Kim Clijsters with a third round stunner over Li Na.
Robson, who had never beaten a Top 20 player before let alone someone in the Top 10, picked up right where she left off against Clijsters, using her big lefty serve and heavy groundstrokes to completely unsettle the flat, powerful game of Li, taking the first set and coming within points of victory leading 3-1 in the second set tie-break; Li took it to a third set but Robson took it up a notch again from 2-all in the third, reeling off four straight games for a 64 67(5) 62 surprise.
"I had the opportunity to win it in two. It was a really close tie-break, and at 5-all she played two really good points," Robson said. "I knew if I kept playing the way I was and kept playing how I started the first set, very aggressive and accelerating on my forehand when I could, I knew she would struggle.
"I wasn't really looking past the first round, and when I heard I was playing Li Na after I played Kim, I didn't really think anything. I just knew it was going to be an extremely tough match, which it was, and that she's a great player.
"I knew I had to play well; that's what I did."
UK soccer star Wayne Rooney sent his support out to his countrywoman Robson over Twitter - well, he intended to support Robson, at least: "Laura Robsinson is playing brilliant good luck Laura," he wrote, followed by a quick apology for the spelling malfunction, blaming it on his phone's predictive text.
"He called me Robinson," Robson said after the match. "I saw that when I was stretching. Can you blame that on predictive text, though? I'm not so sure!
"But it's great that he watched, even though he got my name wrong," she continued. "The more people watch the better - maybe a few people younger than me have seen his tweets and said, 'I want to play a bit of tennis now.'
"I think James Corden was watching me today as well - I spotted him in the first set, and then spent the rest of the time trying not to wave."
Robson is the first British woman to reach the second week of a Grand Slam since Sam Smith made it to the fourth round at Wimbledon in 1998.
Awaiting Robson in the fourth round is another Sam, No.7 seed Sam Stosur, who won a marathon 59-minute first set in a tie-break then cruised past No.31 seed Varvara Lepchenko in the first match of the day, 76(5) 62.
"As the match went on I became a little more comfortable, got used to her spin and the wind a little bit more," Stosur said. "It was tricky out there during the first set, and when it's tight it's hard to really kick start something. But when I got that first set I relaxed a little bit more. Once I got that break it was easier."
Stosur, who has now won 10 matches in a row at the US Open - she won the title here last year - will be playing the young Robson for the first time.
"She's had two of the best wins of her career and she's starting to live up to the potential people have talked about from when she won junior Wimbledon when she was 14," Stosur said. "You can't go into it lightly. You've got to be aware that she's going to come out swinging with that confidence behind her. But you've got to stick to your own guns and play the way you need to play.
"When it comes down to the crunch, back yourself."
Other early winners on Friday were No.5 seed Petra Kvitova, who never faced a break point to beat Pauline Parmentier, 64 64, and No.11 seed Marion Bartoli, who ran off the last four games of the second set from 4-2 down to close out French wildcard Kristina Mladenovic in straight sets, 62 64.
Bartoli leads Kvitova in their head-to-head series, 2-1, but in their only 2012 meeting it was Kvitova who won handily in straight sets a few weeks ago.