Well played drop-shot from Robson. You do get the feeling she is working her way back into this match but could really have done with staying a break in front in this second set.
Far from vintage Laura Robson but Li Na is now serving to stay in this second set.
Fantastic rally in the opening point of the game. Robson looked to have missed her best chance to win it by smashing straight at Li Na but she dispatches her second chance.
A couple of long rallies both go the way of Li Na who appears to be closing in on a place in the fourth round of the US Open. 30-0.
But a brilliant return of serve keeps the game alive. Li Na challenges but to no avail.
Another big serve brings up match point.
But she sends it wide and long! Deuce on the Li Na serve. Can Laura do it?
Another match point as Robson goes long on the second serve.
So there we have it. Laura Robson can't produce the heroics of last year and she falls at the third round stage.
Credit to Robson who still stops and signs some autographs on her way off court. Just not her day today but she will have plenty more.
Congratulations to Li Na. Thanks for following the blog this afternoon and I will see you all again this evening when reigning US Open champion Andy Murray takes on Leonardo Mayer of Argentina. He is likely to be on Louis Armstrong court between 8-9pm.
Welcome back to the live US Open blog. It's Andy Murray time!
For the first time ever, Murray enters a Grand Slam as a reigning champion and will fancy his chances against Leonardo Mayer.
So, who is Leonardo Mayer?
The Argentine is world ranked 81 and reach round 3 at the US Open last year, to equal his best ever Grand Slam result.
Murray and Mayer have met just once before. That was back in 2009 on a hard court in Valencia. Murray took that one by two sets to one.
Andy Murray has won 25 out of 25 second round Grand Slam matches since losing at the US Open in 2005. What odds on an upset today?
If you were interested, Portugal's Carlos Ramos is the chair umpire today.
Leonardo Mayer has played top 10 players on 11 occasions. Record: Won 0 Lost 11
Andy Murray to serve. Here we go.
What a superb rally! Mayer living with the early groundstroke rally against Murray and brings up break point.