By Mark Lamport-Stokes

INDIAN WELLS, California (Reuters) - Revitalised since recruiting a new coach last month, Russian Nadia Petrova has targeted a return to the top 10 in the rankings after three years of relative struggle.

A former top-three player who has piled up 10 career wins on the WTA circuit, the Moscow native ended her 2011 campaign ranked 29th, outside the top 20 for the first time in nine years.

"I really want to get back into top 10, that would be great," Petrova told reporters after upsetting U.S. Open champion Sam Stosur of Australia 6-1 6-7 7-6 in the third round of the Indian Wells WTA tournament on Monday.

"I have been out of that category of players for a couple of years now, and it would be a nice thing for me to challenge the new players, like (Petra) Kvitova and (Victoria) Azarenka.

"They're all young and full of energy. They're hungry for the titles and for number one spot."

The 29-year-old Petrova, who claimed five WTA titles in 2006 on her way to a career-high ranking of third, said she still has unfinished business on the women's circuit.

"I do feel like I'm pushing towards the end of my career but I still know that I have a couple good years left so I want to maximize that," added the big-serving Russian, who prefers playing on hardcourt and clay surfaces.

"I want to give it all, so then I can say I have done it all, with no regrets."

Petrova, who won her first WTA title in almost three years in Washington DC last year, has had an extra bounce in her step since she started working with coach Ricardo Sanchez in Memphis last month.

"I didn't have a coach at the beginning of the year so I felt like I need to do something if I wanted to continue playing well and keep moving forward, because I felt like I was stuck," she said.

"I really wanted to have the best and with Ricardo, I've known him for almost like 10 years. He's worked with great players and I never had an opportunity to work with him. I always wanted to work with him.

"We had a good two weeks' preparation coming into this tournament so I feel much better. Now all I need is just matches."

Petrova, a semi-finalist at the French Open in 2003 and 2005, will play her doubles partner, fellow Russian Maria Kirilenko, in the fourth round at Indian Wells on Tuesday.

(Reporting by Mark Lamport-Stokes; Editing by John O'Brien)