Alexandrova went 4-1 up against Sakkari before a medical timeout was called by the Greek.
Seemingly, she was struggling with a medical issue which promptly saw her decide to retire and with her WTA Finals qualification now secure, she likely did not want to take the risk.
Confirmed list so far for 2021 WTA Finals Guadalajara - Who is qualified and who is missing out?
Now Alexandrova is set to take on Kontaveit who beat Sakkari in the final in Ostrava only a few weeks ago, she breezed past Marketa Vondrousova and now with a WTA Finals spot in her sights, she will aim to see off the Russian tomorrow on home soil.
For Sakkari, she is entered into Courmayeur next week but this is unlikely now to be the case with a mix of this retirement likely due to fatigue and also her qualification for Mexico now being secured.