Watson beaten in titanic struggle after Robson strides into second round

Laura Robson and Heather Watson love the big stage and the British teenagers underlined their burgeoning reputations on their US Open debuts as the year's final Grand Slam event got under way here yesterday. Robson went through to the second round after Japan's Ayumi Morita retired with an injured shoulder when trailing 7-6, 1-0, while Watson came within six points of knocking out Maria Sharapova before the world No 4 won 3-6, 7-5, 6-3 after an enthralling contest that lasted more than two and a half hours.

On a day of glorious sunshine – a total contrast to the weekend, when Hurricane Irene brought high winds, torrential rain and flooding to the city – it seemed for a time that Watson might provide one of the shocks of the year. The world No 102, who is playing in a Grand Slam tournament by dint of her world ranking for the first time, never looked daunted by her task against Sharapova, the tournament's second favourite, in the cavernous Arthur Ashe Stadium.

While Sharapova made frequent errors and struggled with her serve, Watson impressed from the start with her athleticism and bold play. The 19-year-old from Guernsey broke in Sharapova's first two service games and took the first set after 36 minutes.

The crowd quickly warmed to the Briton, who fought back from 4-1 down in the second set. At 5-5 and 30-30 she stood just six points from victory, but Sharapova held serve before breaking to level the match. The former world No 1 took a decisive 3-0 lead in the decider, though Watson continued to push her to the very end and was given a standing ovation when she left the court.

"There's no doubt that she's a great up-and-coming player," Sharapova said afterwards. "She played some of the best tennis today. She played really smart in the first set."

Sharapova is growing accustomed to fending off challenges from young Britons. Two months ago she was made to work hard in the second round at Wimbledon by Robson, who yesterday claimed her first victory over a player ranked in the world's top 50.

There have been times since Robson's triumph in the Wimbledon junior tournament three years ago when it seemed that her progress was stalling, but it is easy to forget her youth. She is the youngest player in the world's top 200 and will not be 18 until January.

Concentrating amidst the noise and commotion that always surrounds matches on the outside courts here can be a problem, but Robson coped well. The match was played on Court 13, which is situated next to one of the main entrances to the site. As well as the noise from passers-by and a steady flow of aircraft overhead flying into nearby La Guardia airport, the players had to deal with the sound of music drifting over from the adjoining main concourse.

The players wore identical pink outfits but their games were very different. Robson relied on her big serve and thumping ground strokes, while Morita, a compact bundle of energy, made up for a lack of killer shots with her consistency and relentless chasing.

Robson, who earned her place in the draw by winning three matches in qualifying, got off to a flier, breaking serve for a 2-0 lead with some thumping returns, but then lost four games in a row as she struggled with the ball toss on her serve. Morita served for the set at 6-5, but Robson hit some splendid returns to force a tie-break.

By now the Briton was finding a better rhythm and on her second set point she hit a booming service winner. There had been no sign that Morita had any problem with her shoulder until she sent for the trainer after Robson broke her to love in the opening game of the second set, after which the world No 46 quit.

"I actually wasn't that nervous," Robson said afterwards. "I think I always get much more nervous at Wimbledon because it's sort of a much bigger occasion. But I think it has helped a lot that I've already played three matches here and I already know how to play on these courts."

Robson now plays Spain's Anabel Medina Garrigues, the world No 33, who beat Italy's Karin Knapp. Currently at a career-high No 173 in the world rankings, Robson could move into the world's top 150 just on the strength of her victories here so far.

Petra Kvitova became the first reigning Wimbledon champion to lose in the first round here in the Open era when she was beaten 7-6, 6-3 by Romania's Alexandra Dulgheru. The Czech has won only two matches since her victory at the All England Club.

Mardy Fish, the highest-ranked American, dropped just five games in beating Germany's Tobias Kamke. Andy Murray will play his opening match against India's Somdev Devvarman tomorrow.