The Russian, playing her second tournament since returning from a drugs ban, came from behind to beat Mirjana Lučić-Baroni of Croatia at Park Manzanares in Spain's capital.

The 30-year-old five-time grand slam champion won 4-6, 6-4, 6-0 in the round-of-64 clash.

She will now meet Canada's Bouchard who has criticised the way Sharapova has been welcomed back to the sport following her 15-month suspension for meldonium.

The London 2012 Olympic silver medallist was given a wildcard for the Porsche Grand Prix in German city Stuttgart last month, which was her first tourmament back after her ban and saw her reach the last four.

Organisers in Madrid also handed the Russian automatic entry, meaning she did not have to come through qualification.

"She's a cheater and I don't think a cheater in any sport should be allowed to play again," Bouchard, a 2014 Wimbledon finalist, told TRT World last month.

The Canadian booked her place through by beating Alizé Cornet of France 6-4, 4-6, 6-1 at the clay court tournament. 

Other players to advance today included Romania's third seed Simona Halep who ousted Karolína Plíšková of the Czech Republic 6-1, 6-2.

German top seed Angelique Kerber defeated Hungary's Tímea Babos 6-4, 6-2.

Denmark's Caroline Wozniacki also came through, beating Romanian Monica Niculescu 7-5, 6-7, 6-4.

Two men's first round matches also took place today.

David Goffin of Belgium knocked out Russia's Karen Khachanov, 6-2, 7-6.

Italy's Fabio Fognini was also successful, beating João Sousa of Portugal 6-4, 6-4.

Competition at the Women's Tennis Association and Association of Tennis Professionals Masters 1000 event continues tomorrow.