Tennis news - Friends and opponents pay tribute to Maria Sharapova

Novak Djokovic, who has long been a friend of Sharapova's, encouraged the crowds at the Dubai Duty Free Tennis Championships to applaud her achievements.

"She's a great fighter, as dedicated as someone can really be in our sport, the willpower and the willingness to overcome all the obstacles that she had, especially in the last five, six years with injuries and surgeries...it's truly inspirational to see what a mind of a champion she has," he said.

Petra Kvitova, who beat the Russian in the 2011 Wimbledon final, gave her reaction after winning her Round of 16 match at the Qatar Tennis Open.

"I know how tough it is to come back and play and she has been injured a lot and of course she wanted probably bigger success than she really [had] or the body allowed her to have," said the Czech, who returned to the tour after a knife attack by an intruder left her with serious injuries to her left hand.

"So she achieved a lot in her life so far and she still [has] so many things to do, even after tennis. So for me it was [a] pleasure to be with her on the tour, sharing the court with her. It was always great battles when we [played] together. She's a big hitter as well, so it's been always nice to share the court with her and I do always have respect to her.

"She [has] been [an] amazing competitor, she never [gives] up. Even when she didn't play well, she was still believing in her game and still being aggressive and believing in her shots, which I'm really admiring."

Chinese star Zheng Saisai said that she had always looked up to Sharapova, and admired her attitude.

"She never gives up, she's always there, doesn't matter 1-5, doesn't matter the scores - her mentality always...inspires us to try to be the same mentality, from the first point to the last," the 26-year-old said.