Chanelle Scheepers of South Africa and Maria-Teresa Torro-Flor of Spain won in straight sets Monday at the Grand Prix SAR.
Scheepers and Torro-Flor will meet in the second round.
Scheepers beat second-seeded Sorana Cirstea of Romania 6-3, 6-1, and Torro-Flor defeated Arantxa Rus of the Netherlands 6-1, 6-1.
Scheepers had four aces and broke six times against Cirstea, who won their only previous meeting on hard courts two years ago at Brisbane, Australia.
Rus struggled on serve, double-faulting eight times and winning only 50 percent of first-serve points.