INDIAN WELLS, CA, USA -- A blockbuster first-round draw between two Top 50 stars at the BNP Paribas Open went the way of Naomi Osaka on Wednesday night, as the 20-year-old from Japan defeated five-time major champion Maria Sharapova of Russia, 6-4, 6-4.

“I knew [Sharapova] would fight for everything because I’ve watched her since I was little," Osaka said, directly following the match. "I was just really honored to play her.”

Osaka elaborated on Sharapova's grit in her post-match press conference. "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."

The Russian admitted she had found the encounter 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," she said afterwards.

“It hasn’t been an easy couple of weeks since Doha, 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.

Osaka reeled off eight of the first nine points of the match en route to a 2-0 lead, as the Japanese player started the encounter hitting fiery winners off both wings, while Sharapova, who won the BNP Paribas Open title in 2006 and 2013, struggled with unforced errors and inconsistent serving.

A scorching reflex passing shot winner propelled Osaka to a hold for 4-1, and the younger of the two players appeared to have Sharapova’s number on the day. But the Russian regrouped, and collected herself to summon some blistering service return winners and break to get back on serve at 4-3.

Serving at 4-4, Osaka initially fell behind with a backhand error, but regained her composure to hit more forehand winners to hold for 5-4. In the next game, Sharapova faltered, hitting two unforced errors and a double fault to give Osaka double set point. An additional unforced error off the backhand of the former World No.1 handed the opening frame to Osaka.

Osaka jumped out to an early advantage in the second set, when she broke Sharapova at love for a 3-1 lead, polishing off the game with a backhand winner down the line. But the Russian quickly broke back, as Sharapova once again started to hit exceptional service returns off of Osaka’s weaker deliveries.

The two players exchanged breaks once more, as the unforced errors from both sides continued to mount, and the aggression on return ramped up once both players grasped the enormity of this stage of the set.

But, finally, it was Osaka who took control at the end. Serving at 4-4, 30-30, another daring passing shot off the backhand side helped her win another close game, putting her a game away from victory and forcing Sharapova to serve to extend the match.

In the next game, the Russian crushed a backhand winner down the line to put her a point away from 5-5, but an unforced error pulled the game back to deuce. On the next point, Sharapova hit a costly doubt fault, giving Osaka match point. A final unforced error from the Sharapova backhand sent the gleeful Osaka skipping into the second round.

"I feel like I tried a lot to sort of change the way I think," Osaka told the media. "Before, if maybe she came back from that [deficit], I feel like I probably would have gotten really upset. I’m just really happy I was able to win and change the way my mentality works."

More first round recaps:
Vickery victorious against Bouchard, gets Muguruza next
Bencic bests Babos in marathon Indian Wells opener
Dolehide fights back to beat Rogers as Anisimova seals historic victory