Former world No.1 Maria Sharapova has eased past fellow Russian Ekaterina Makarova 7-5 6-1 to reach the Stuttgart Grand Prix quarter-finals and continue her winning comeback from a 15-month doping ban.

The 30-year-old Russian, who has won five Grand Slams and is among the highest-paid athletes in the world, returned to action on Wednesday with a straight sets win over Roberta Vinci following her suspension for the use of banned substance meldonium.

Sharapova, who had tested positive at the 2016 Australian Open, picked up where she had left off against Vinci, powering through her first two service games without dropping a point but struggling somewhat with her return consistency.

Makarova also cleverly mixed up the height and depth of her shots during rallies on the quick Stuttgart clay with Sharapova still lacking match practice.

Makarova wasted her only break opportunity at 5-5 and Sharapova never looked back. She earned her first break points a game later, powering a crosscourt forehand winner to grab the first set.

She broke Makarova twice in the second set to race 5-1 ahead and served out the match with an ace to set up a quarter-final clash against Estonian qualifier Anett Kontaveit.

Johanna Konta was knocked out of the second round in straight sets by Latvia’s Anastasija Sevastova.

The British No.1 is inexperienced on clay at the highest level and it showed in a scrappy 6-3 7-5 loss to Sevastova, who also won their meeting at the US Open last year.

Wednesday’s first-round victory over Naomi Osaka in Stuttgart was just Konta’s third WTA Tour win on clay.

Elsewhere, Carla Suarez Navarro was too good for Elena Vesnina, while Germany’s Laura Siegemund sprung an upset on eighth seed Svetlana Kuznetsova with a 6-4 6-3 win.