U.S. Open champion Samantha Stosur bowed out of the China Open after losing to Maria Kirilenko from Russia in the second round on Tuesday.

The China Open, which ran in its eighth year, has lost world number one Novak Djokovic, Maria Sharapova and the Williams sisters to injury or weird illness. It was then followed by early upsets from reigning Grand Slam winners Li Na (French Open) and Petra Kvitova of Czech Republic (Wimbledon).

There was another surprise on the fourth matchday of the elite tournament when world number seven Stosur went down to the 27th ranked Kirilenko 7-5, 1-6, 7-5 after two hours' battle.

"I've only played two tournaments since winning the U.S. Open so it's not the end of the world. Obviously I wanted it to be a lot better than what it has been, but I guess it's one of those things," Stosur said.

With the convincing victory, Kirilenko, the 2005 China Open champion, improved her record against Stosur to 4-4.

"I played against her eight times in my life and now we have an even score in all matches. I know how she's playing, nothing new," Kirilenko, 24, commented on the rivalry.

Stosur shared the same sentiment with Kirilenko, "I don't think there's anything really bad with the tactics going out to play Maria. I think in the U.S. Open I won in three sets; last week I lost 6-4 in the third, so there is reall not a lot in it. It's just a matter of at those crucial times doing my game plan and really sticking to it when it really matters."

Stosur made a flying start at the opening set, notching up a break in the fourth game to lead at 3-1, but it was just a flash in the pan as the Australian, who claimed the first Grand Slam title in career in the U.S. Open, was troubled by too many unforced errors in the following play of the set.

Kirilenko, who has just defeated the Australian in the Pan Pacific Open in Tokyo a week ago, was not affected by the slow start and raised her level with a more aggressive game. She mixed attacks from the baseline with net approach and broke back two times in seventh and 11th games before clinching the set at 7-5.

Stosur finally produced an impressive display from baseline and called the shots in the second set, converting on three out of six break points to take it at 6-1.

The deciding third set was hotly contested, with Kirilenko first storming to a 3-0 lead and then Stosur breaking back to level at 5-5.

The final two games was just a replica of those in the opening set, seeing Kirilenko break first and then serve for the match.

"I did't get off to as good a start as you want going into a third set. 3-love down and then 5-2 down, that's not a deficit you want to be in when it's the last set of the match," Stosur said of the final set.

"I got it back to 5-all and started playing quite well again and really felt like I was on top of it. Unfortunately I didn't play a great game at 5-all and I think I had chances to do a little more with the ball but I didn't," added Stosur.