Top seed Iga Swiatek fought back from a set down against Beatriz Haddad Maia to book her place in the Madrid Open semi-finals.
After sweeping past Spain’s Sara Sorribes Tormo in just 68 minutes on Monday, Swiatek needed two hours 30 minutes to wrap up a 4-6 6-0 6-2 win against the Brazilian.
It was the first time the world number one dropped a set in the tournament.
Swiatek will face Tunisian eighth seed Ons Jabeur or American 18th seed Madison Keys, who play later on Tuesday.
The 22-year-old Pole, bidding for her third title of 2024, broke first and raced to a 4-1 lead, but Haddad Maia eventually found her rhythm and reeled off five consecutive games to take the opening set.
However, the 11th seed won just 12 points in the second set as Swiatek claimed a 6-0 bagel.
After exchanging breaks early in the decider, Swiatek broke for a 3-1 lead before striking again at 5-2 to reach her fifth semi-final of 2024.