Sharapova stunned in first round of BNP Paribas Open

Naomi Osaka of Japan caused a major upset at the BNP Paribas Open as the 20-year-old defeated five-time Grand Slam champion Maria Sharapova of Russia 6-4, 6-4 in Indian Wells, California on Wednesday.

"I knew Sharapova would fight for everything because I've watched her since I was little," Osaka said after the match. "I was just really honored to play her," the Japanese star said.

"Everybody knows that she fights for every point, so I just tried to tell myself if I fight for every point too, then it could be an equal match," she added.

The Russian admitted the encounter was frustrating. "I've been working through a few physical things and that's been frustrating because there's been a lot of starts and stops since I've come back and that hasn't really given me the type of playing match rhythm that I really wanted, but I felt like I committed today and there are a lot of good things that I can take away," Sharapova said afterwards.

"It hasn't been an easy couple of weeks trying to get healthy, but it's there, I need some time. I've done it before. It's obviously frustrating to lose these types of matches that you get ready for and you want to win but it's part of the process, I realise that."

In the first meeting between the two power hitters, it was the Japanese youngster who emerged victorious in the cool conditions at Indian Wells, in one hour and 37 minutes. Osaka won a superb 75 percent of points when facing the Sharapova second serve.

Osaka will take on former world No.2 and No. 31 seed Agnieszka Radwanska in the second round. The 2012 Wimbledon runner-up from Poland will face Osaka for the first time after her opening-round bye.