Former world number one tennis stars Maria Sharapova lost her second consecutive first round match with a 6-4, 6-4 defeat to Japan’s Naomi Osaka at the BNP Paribas Open in California on Thursday. Sharapova, who returned to tennis last April following a 15-month doping ban, continued to struggle to find form this season as she dug herself into an early hole and never fully recovered.

Now ranked 41st in the world, Sharapova fought back from early breaks in both sets but ultimately came up short on the key points in a performance that saw her commit six double faults and lose five service games to her 20-year-old opponent.

“I knew (Sharapova) would fight for everything because I’ve watched her since I was little,” world number 44 Osaka said in an interview after winning the first meeting between the pair. “I was just really honored to play her.”

A two-time champion at Indian Wells, Sharapova won the Tianjin Open in October for her first triumph since returning to the WTA Tour, but has not come close to challenging for a tournament victory since. In earlier action, American teenager Amanda Anisimova recorded her first top-level victory with a 6-2 6-2 thrashing of Pauline Parmentier. The 16-year-old’s poised and polished performance came in stark contact to the dismal display of Canadian Eugenie Bouchard, who was humbled 6-3 6-4 by American qualifier Sachia Vickery.