On another rain-interrupted day, Ferrer beat Simon Greul of Germany 6-3, 6-4, conceding only 10 points on serve, and Baghdatis fired 12 aces and didn't lose serve in dispatching local wild card Raven Klaasen 6-3, 7-5.
In Baghdatis' first quarterfinal since June, he will meet Ferrer, who won their only previous matchup three years ago.
In first-round matches, third-seeded Marcel Granollers of Spain was upset by 225th-ranked French qualifier Sebastien de Chaunac 7-5, 7-6 (3), and South African wild card Izak van der Merwe outlasted Benjamin Becker of Germany 7-6 (4), 7-6 (3).
Ferrer, Baghdatis progress to Joburg quarters
Antonio Hidalgo Looking For Playing Time With Osasuna
Ferrer, Baghdatis progress to Joburg quarters
Player Ratings: Racing Santander 1-2 Barcelona
