Misaki Doi upset the odds to defeat Jelena Jankovic 7-6 (7-4) 7-5 and move into the semi-finals of the Luxembourg Open on Friday.

Jankovic had plenty of reason to be confident having beaten Doi on their previous two encounters, while she also won the Guangzhou Open last month.

However, the world number 22 was shocked by a plucky performance from the Japanese, who is ranked 70 spots below her opponent.

There were seven breaks of serve in an error-strewn encounter, but Doi held her nerve when it counted and can look forward to a last-four showdown against Alison Van Uytvanck after the Belgian beat seventh seed Barbora Strycova 6-4 6-4.

On the other side of the draw Mona Barthel beat Mirjana Lucic-Baroni 6-3 6-4, and will now meet Stefanie Vogele in the last four after she lasted the distance in a 6-4 2-6 6-1 triumph against Laura Siegemund.