Karolina Muchova fought back to stun world number one Ashleigh Barty at the Australian Open and reach her maiden Grand Slam semi-final.
The Czech 25th seed struggled with dizziness in the Melbourne Park heat but refocused after a medical time-out to beat the home favourite 1-6 6-3 6-2.
Barty led by a set and a break but was unable to stop Muchova's comeback.
Muchova will play American Jennifer Brady, who beat compatriot Jessica Pegula, for a place in the final.
"It was very tough and I was a bit lost on the court and my head was spinning so I took a break," the Muchova said.