“I've had easy scores until now, but it doesn't mean I've had easy matches," Radwanska said.
"I played great tennis, especially today, and Yanina was a tough opponent - every time we play I have to really push myself 100% to beat her. I think I just played really, really good tennis out there tonight.”
Radwanska will face Simone Halep in the semi-finals after the Romanian came through her clash with fourth seed Sara Errani in impressive fashion, winning 6-2 6-0.
"It was a difficult match. I couldn't prepare very well because I'm not 100% - I have an injury - and I can't run very well on the court," Halep said.
"But I was very strong mentally and just wanted to focus on every point. She's a great player and comes back very well and runs very well, so I knew it was important to just stay aggressive and finish the points, and the match, as soon as I could."
Qatar Open results
2-Agnieszka Radwanska (Poland) beat Yanina Wickmayer (Belgium) 6-2 6-1
7-Simona Halep (Romania) beat 4-Sara Errani (Italy) 6-2 6-0
5-Jelena Jankovic (Serbia) beat 3-Petra Kvitova (Czech Republic) 6-1 6-3
6-Angelique Kerber (Germany) beat Petra Cetkovska (Czech Republic) 6-1 6-0
- Sports & Recreation
- Sara Errani
- Petra Cetkovska