Heather Watson blown away after cloudburst

Heather Watson was beaten in straight sets by Li Na yesterday (Getty Images)

Two months after becoming the first British woman for 10 years to reach the third round at Wimbledon, Heather Watson lasted just 81 minutes on the first day of the US Open here yesterday.

The 20-year-old from Guernsey, who was overpowered 6-2, 6-3 by China's Li Na, held on until mid-afternoon thanks only to a lengthy rain delay.

If Watson took advantage of a favourable draw at the All England Club – her first two opponents were both ranked outside the world's top 50 –fortune was not on her side here. Li, the world No 8, has been the outstanding player on the north American hard-court circuit this summer, reaching the final at Montreal and then winning at Cincinnati to secure her first title since last year's French Open.

She had too much firepower for Watson, who never looked like threatening the 30-year-old Chinese in the way she had troubled Maria Sharapova last year, when the Briton went within six points of causing one of the shocks of the tournament. Striking the ball beautifully from the back of the court, Li cracked 28 winners to Watson's 10 and broke serve five times.

At least it will not be the end of the tournament for Watson, who is playing doubles here with New Zealand's Marina Erakovic. They have won two doubles titles together this summer, in Stanford and Dallas.

Li has recently teamed up with Carlos Rodriguez, who was Justine Henin's long-time coach. Rodriguez, who had said on the Belgian's retirement that he could not imagine coaching any other player, has been working at an academy in Beijing for the last two years.

The association has brought immediate success and Li's renewed confidence was evident in her ball-striking. Watson, who at No 71 is the world's highest-ranked British woman, kept up with the pace for four games, but from 2-2 Li put her foot on the accelerator, winning four games in a row to take the first set in 36 minutes.

Watson made an early break in the second set to lead 3-1 but did not win another game. A swift finish looked likely until rain started to fall with Watson trailing 5-3. The subsequent interruption of nearly three hours only delayed the inevitable. Watson won just one more point on the resumption before Li closed out victory.

"I'm happy with how I played," Watson said afterwards. "I even feel I played better today than I did last year against Maria. I don't think it was Maria's best match last year, but today Li Na was on another level. She was hitting winners off balls I wouldn't think you could hit winners off, hitting lots of lines. She had a really high first-serve percentage and she just played better tennis. She played like a Grand Slam champion."

On a bad day for German tennis, Julia Goerges and Sabine Lisicki, who are both seeded, lost to the Czech Republic's Kristyna Pliskova and Romania's Sorana Cirstea respectively. Another German, Andrea Petkovic, who was in the world's top 10 last year but has been troubled by injury, was beaten by Switzerland's Romina Oprandi.