Swiatek into semis after Wozniacki retires injured

World number one Iga Swiatek went through to the last four at Indian Wells as Caroline Wozniacki retired injured from their quarter-final.

Poland's Swiatek came from 4-1 down to take the first set 6-4 before Denmark's Wozniacki required a medical timeout.

The former world number one played on but managed just one more game, which she lost, before having to pull out.

Swiatek has reached three consecutive semi-finals in California and will take on Ukrainian Marta Kostyuk on Friday.

Kostyuk, the 31st seed, secured a first WTA 1,000 semi-final appearance with a 6-0 7-5 win over Russian 28th seed Anastasia Potapova.

US Open champion Coco Gauff takes on Yuan Yue in the last eight later on Thursday.