US Open: Laura Robson v Sam Stosur as it happened

Sam Stosur, seventh seed and defending champion, serving for the match. She's been in this situation many a time before but Robson whips the crowd into a frenzy with a backhand winner for 15-15. "Ohhhh," squeak a few spectators as a Stosur forehand winner grazes the line and the Australian follows it up with a colossal serve, which Robson frames. Two match points. "It ain't over yet, buster," says the Brave Brit, or something like that, as she saves those two match points and fabulously conjures a break-back point - which she grabs when a Stosur backhand limps into the tramlines. Incredible! Robson has, in the last two games, saved seven match points. Tennis is better than chips. Official.

Can Robson, the youngest player remaining in the women's side of the draw and the youngest woman inside the top 100, hold her nerve and force Stosur to serve for the game? Erm, the alarm bells begin to sound as a wayward backhand followed by an equally clumsy forehand moves Stosur to 15-30. The defending champion then ekes match point... Robson's first serve is off target... the tension is cranked up a notch... but she wriggles free for deuce. Robson, bending her knees, nets a backhand to gift Stosur another match point. Danger averted, but it's only a temporary reprieve as a forehand winner, full of top spin and menace, earns Stosur a third match point. Cripes. The spirited Robson saves two further break points - serving into the Stosur backhand saving her bacon - and a wayward Stosur forehand ensures Robson holds!

A textbook service game from Stosur who finishes with an ace for another magical hold to love. She's now a game away from victory.

Robson looking as if she's climbed to the 54th floor of the Empire State Building only to realise she's barely got halfway. At 30-30, Robson steadies herself on the baseline, breathes deeply, before serving to the wings and then unleashing an unstoppable winner into the corner beyond the lunging Stosur. A double fault, though, sets the nerves jangling - but there's no need to worry as another serve out wide followed by a forehand winner sees Robson home.

Is Robson's glorious late summer in New York about to end? Her challenge is certainly waning as Stosur holds to 15, edging closer to the quarter-finals after just over an hour on Louis Armstrong.

A couple of sloppy groundstrokes eases Stosur to 0-30, but parity is restored and a fortunate net cord inches the 18-year-old to 40-30. The Brit tosses the ball high into the New York sky but thinks better of serving so steadies herself and starts again. Tension. Stosur engineers a break point and Robson wobbles, sending a looping backhand long.

Robson's groundstrokes are now as accurate as they were at the start of the first set. The Londoner, gambolling on the baseline, nicks two break points - which Stosur saves. Another break point... another save from the streetwise Stosur and the champion then serves into the wings to wrong-foot Robson and limp over the line.

Robson has been in confident mood in New York, admitting she does not feel out of place mixing it with the big names. "Whenever I've practised with Caroline [Wozniacki] or Maria [Sharapova], I've always felt the level was there," the world number 89 has said. Robson's serve, more often than not, is certainly there. One into Stosur's ribcage... and the Australian's backhand return plonks into the tape, allowing Robson to halt a three-game losing streak.

Stosur, red visor and sporting a grey dress with red straps which has been her uniform at Flushing Meadows, has found her radar and is using the kick serve to good effect. An ace down the 'T' eases her to 40-30 and Robson, being overpowered at the moment, then nets for a trouble free hold to the Aussie.

The teenager serving to stay in the set... and the Brit decides to remain rooted to the baseline. Robson overcooks a forehand which means Stosur has fashioned three break points. Forehand down the line. One saved. A Stosur forehand bounces long. Two saved. But the Brit double faults to meekly award the set to the defending champ.

Groans from the crowd as Stosur scampers to the net and hits a half volley into the tape, gifting Robson a break point. The Australian, first serve faltering a tad, takes the game to deuce but a sumptuous backhand winner into the corner earns Robson another break point. Stosur saves, finds her rhythm and Robson can only tamely net the next two returns.

Robson serves out wide and, with Stosur lunging to her left, the Brit unleashes a forehand winner into the corner. Robson holding her own against a more experienced opponent.

The pair, it seems, were just sparring in the opening couple of games, working each other out. They're now serving at full pelt and a howitzer of a serve into the wings secures another hold to love for Stosur. Steady on, girls, I'm having trouble typing at such speed - especially on a Sunday.

Robson, the first British woman to defeat a top 10 opponent at a Grand Slam since Sam Smith at Wimbledon in 1998, has Stosur on her heels and is finding the corners wonderfully with that venomous forehand of hers. A cool ace to classily finish a comfortable hold to love.

Hmmm... Robson seemed in control of her last service game, but Stosur is the seventh seed and reigning champion afterall so she's not going to throw in the towel at this stage of the match, if ever. A Robson return bounces long and it's a straightforward hold to love for the Aussie.

A clutch of latecomers halting play for a few seconds, but not even tardy ticket holders can stop the Robson steam train. She's chugging along nicely. The defending champion's returns finding the net with worrying regularity but - hang on, a double fault and a tame backhand into the tape and we're at deuce and, in a blink of an eye, the Australian has broken back.

Stosur - who beat Serena Williams in last year's final to become the first Australian woman since 1980 to win a Grand Slam single title - admits Robson will be a "tricky" opponent because the Briton has nothing to lose. "You can't go into it lightly," she said ahead of this match. The Australian-born Brit certainly swinging from the hips at the moment and nicks two break points, taking her second chance with a whizzing winner into the corner which Stosur can only frame. Impressive. Very impressive.

Stosur having difficulty returning those powerful Robson serves and the world number 89 whacks a forehand winner into the corner for a nerveless hold in front of a sizeable crowd on Louis Armstrong.

Robson, of course, is the first British woman to reach the fourth round of the women's singles at Flushing Meadows since Jo Durie 21 years ago. The Brit wasn't even a twinkle in her father's eye back then. The teenager's colossal forehand is on song, but a backhand down the line drifts beyond the baseline and it's first game to Stosur.