It was the Italian who faltered at the close, not the British player.

Schiavone was an unpredictable, impulsive opponent – but then what do you expect from someone who likes to relax away from the courts by driving her car extremely fast? But then again, maybe that is just Italians for you. Keothavong, though she trailed 4-2 in the final set, won the next four games. On the Briton’s first match point, Schiavone’s serve struck the white tape of the net and flipped up and over the service-line.

Keothavong didn’t care how the win transpired, just that she had completed the 6-2, 3-6, 6-4 win, making her the first British woman to reach the third round here since Jo Durie and Sara Gomer did it 17 years ago. She also became the first British female to reach the last 32 at any slam since Elena Baltacha came through qualifying for the 2005 Australian Open and then won a couple of rounds in the main draw. But Keothavong was not on court just to be a "first since".

Keothavong, who gained direct acceptance into the main draw and who is ranked 87 in the world, has ambitions of breaking into the top 50, and those ambitions do not look unrealistic. The points she has gathered here should take her ranking up to around 75. More importantly, she has discovered that she can live at this level. Next up for Keothavong is Elena Dementieva, a former finalist at the US Open and more recently a gold medallist in Beijing.

When Keothavong remarked here that the US Open was one of her favourite tournaments, that was before she had even made her first appearance in the main draw. In fact, this week saw her first main draw grand slam showing away from the grass courts of the All England Club. But you can be sure that her affections for Flushing Meadows have grown. The speed and the feel of the courts here are suited to her game, and Keothavong achieved the best win of her career — never before had she beaten anyone as highly ranked as Schiavone.

When Justine Henin retired this year, Schiavone became the highest-ranked player to use a single-handed backhand. Still, the Italian’s backhand isn’t nearly as effective or as beautiful to watch as Henin’s, and in the early stages she was misfiring on that side, and on her forehand too.

Schiavone’s frame was getting more play than the strings – she started the opening game with a duff forehand and then a flunked backhand and was broken to 15. Keothavong’s tennis was much smoother, and she soon found herself serving for the first set at 5-2. That service game became a mini-epic of its own. Although Keothavong quickly reached 40-0, closing out the set didn’t prove to be easy, as it was only after three break-points and seven set-points that was she was able to finish it off.

So Keothavong was now halfway to making the third round on New York’s concrete. The second set didn’t go to plan, though, as Schiavone’s tennis had improved as the match continued and she won the first four games of the second set. When she was 4-1 up, Schiavone left the for court for an extended bathroom break, leaving Keothavong to serve away at an unprotected backstop as she waited. On the resumption, Keothavong held serve, but she couldn’t do anything about the set. So the match went to a decider, and Schiavone took a 4-2 lead. But after that the Italian didn’t win another game.

In the lunch time heat, spectators were taking shelter from the sun under the courtside trees, looking on as Keothavong provided the stronger finish.

"That was very impressive," said Carl Maes, the head of the women’s game for the Lawn Tennis Association.