Sara Errani remains on track at the Rio Open after saving three match points to reach the semi-finals on a good Friday for the seeds.

The Italian top seed led local Beatriz Haddad Maia 3-6 7-6 (7-2) 3-0 before the Brazilian retired, citing cramping after two hours, 17 minutes on the clay courts.

Errani had broken twice to start the third set, losing just two points, before the 18-year-old world number 234 called it quits.

The world number 16 had been pushed and needed to save three match points in the second set on her way to the last four.

Errani will face Johanna Larsson in the semis after the Swedish fifth seed beat German Dinah Pfizenmaier 6-4 6-0.

A win had looked unlikely for Errani.

Wildcard Haddad Maia, a two-time French Open junior runner-up, showed no nerves on her way to a 4-0 lead in the first set.

While she coughed up one of those breaks, she saw out the set by holding to 30 in the ninth game.

Each of the first seven games in the second set went against serve, and Haddad Maia looked in control when she took a 5-3 lead.

Errani recovered from 15-40 down to hold in the ninth game and then broke to love for 5-5.

Haddad Maia served for the match again at 6-5 and had another match point, but she was broken after a 16-point game.

And Errani cruised through the tie-break before dominating the start of the third set, prior to Haddad Maia retiring.

On the other side of the draw, Irina-Camelia Begu will face Anna Schmiedlova in a semi-final.

Sixth-seeded Schmiedlova brushed past Paraguayan qualifier Veronica Cepede Royg 6-3 6-1 and Begu, the second seed, thrashed Julia Glushko 6-1 6-2.