A disappointed Li Na admitted to an attack of stage fright in her humbling US Open semifinal loss to Serena Williams and said she would have lost to any opponent she faced on Friday.

The first Chinese to reach the last four at Flushing Meadows, a shell-shocked Li crumbled 6-0, 6-3 in 87 minutes on Arthur Ashe Stadium's center court.

The 31-year-old has long been accustomed to the glare of the Grand Slam spotlight, winning a French Open two years ago and reaching her second Australian Open final this year, but was already overwhelmed by the occasion before hitting a ball.

"It's not about the technique," Li said. "It's about the problem with myself.

"It was my first time in the semis, so I was thinking about the situation.

"Today it doesn't matter who the opponent is. The problem is myself."

Asia's first Grand Slam singles winner, Li lost the first set in 29 minutes and despite taking an early break in the second set, slumped to 5-2 and the brink of defeat.

Only then did she produce her best and most aggressive tennis, saving six match points and forcing defending champion Williams to serve out the match.

Currently ranked No 6 in the world, Li has blown hot and cold throughout her career.

Her seven WTA singles titles have often been bracketed by wretched form slumps when her confidence deserts her.

"Even if today I was playing against (a player with) the ranking of 100, (there would) still (be) the same problem," she said.

"When I walked to the court, I was feeling like the court was so big. My side was feeling like a football court.

"I could not focus. But in the end, finally I could play tennis."

(China Daily 09/08/2013 page7)