Luxembourg - Misaki Doi of Japan upset fifth-seeded Jelena Jankovic of Serbia 7-6 (4), 7-5 to reach her first Tour semi-final this season at the Luxembourg Open Friday.
The 92nd-ranked Doi, who rallied from a break down twice in the third set to get past fourth-seeded Andrea Petkovic in the first round, broke Jankovic four times to set up a semi-final against Alison Van Uytvanck of Belgium.
Van Uytvanck, a quarter-finalist at the French Open this year, beat seventh-seeded Barbora Strycova of Czech Republic, 6-4, 6-4.
The other semi-final at the indoor tournament will pit together Mona Barthel of Germany and Switzerland's Stefanie Voegele.
Barthel eased past Mirjana Lucic-Baroni of Croatia, 6-3, 6-4 while Voegele progressed with a 6-4, 2-6, 6-1 win over German Laura Siegemund.