Maria Sharapova rejected a comparison with veteran grand slam champion Roger Federer after continuing her successful comeback at the Stuttgart Open on Friday.

Sharapova defeated Anett Kontaveit 6-3 6-4 to reach the semi-finals of the WTA Premier event, having been handed a controversial wildcard entry following the completion of a 15-month doping ban.

Federer captured the Australian Open in January in his first tournament back from a knee injury before triumphing at ATP 1000 events in Indian Wells and Miami, and Sharapova's own return looks set to culminate in success.

But the Russian, speaking in an on-court interview, tactfully played down any parallels with the Swiss great.

"I can't compare myself to Roger Federer," she said.

"That would be a really nice compliment. You want to follow in those footsteps because he always sets the highest example and it would great to have the kind of comeback he's had."

Asked what enabled her to make such an impression despite having gone for more than a year without testing herself against the best, she said: "I think it's part of being a competitor. We all work too hard not to come out here and give it everything you have until the last point. We owe it to ourselves because of the dedication we have as professional athletes."

Sharapova revealed she took only minimal interest in watching the exploits of her fellow professionals during her enforced absence.

"I definitely watched some of the grand slam matches but not too much actually," she said.

"I gave myself a little bit of a break to do other things. I still kept in shape. But it was nice to put the rackets away for a little bit. That was a little bit of a relief for a few months. But I love the game and I love great rivalries."