Tokyo:Jelena Jankovic's hopes of regaining her world number one spot this week ended on Friday when she crashed out of the Pan Pacific Open tennis tournament to Svetlana Kuznetsova in the quarter-finals.
The Serbian top seed, who could have regained the top spot by winning in Tokyo, hit two double-faults on a break point before losing 2-6, 7-5, 7-5 to the fifth-seeded Russian.
Jankovic had to crawl back from a break down in each set and at 5-5 in the second set she hit her sixth double fault on an advantage point for Kuznetsova before the Russian held her own to even the score.
Jankovic came back from a break down three times in the final set, but again hit a double-fault at 30-40 in the 11th game to go down 5-6.
Kuznetsova, who avenged her Olympic loss to China's Li Na in the first round, made no mistakes in the following game, hitting a backhand passing shot at 40-30 to finish off the two-hour-26-minute battle.
"It was a tough match for me. I had my opportunities. I wanted to win, of course, it just wasn't my day," said Jankovic, 23, who became the world number one for just one week during the Beijing Olympics.
"She played really solid tennis today. It was very close, unfortunately it went her way.
"The percentage of my serve was getting lower and lower, then in the third set I made a lot of double-faults. I don't know why, maybe because I was a little bit tired."
Asked about missing the chance to regain the number one ranking, she said "That doesn't matter because I still have five tournaments until the end of the year."
"It's not important to be number one at the moment but I'd like to finish number one at the end of the year. That is, for me, the most important thing," she added.
Kuznetsova said: "She was the most consistent this year, she played very good. It's never easy because she brings all the balls back. I'm very happy with my performance, the way I was attacking all the time."
In the semi-finals on Saturday, Kuznetsova will meet either Russian Olympic gold medallist and third seed Elena Dementieva or Katarina Srebotnik of Slovenia.