BOL, Croatia - Slovenian teenager Kaja Juvan sprung another surpise to reach the semifinals of the Croatian Bol Ladies Open.

The 18-year-old defeated No.3 seed and former champion Aleksandra Krunic, 7-5, 6-3, in Friday's quarterfinals to become the lone unseeded player among the semifinalists.

The teenager blitzed through her first two rounds, defeating Tamara Zidansek and No.5 seed Astra Sharma with the loss of a combined three games, and continued her good form against the World No.76.

Juvan was quick out of the gates again on Friday, as she held and broke the Serbian in her first service game to establish an early lead.

She was broken when she served for the set at 5-3, as Krunic won two straight games at love to level at 5-5, but the teenager would not be denied the opening set as she broke again in the set's final game.

Juvan saved the lone break point she faced in the second set, in the third game, and broke Krunic immediately after to take a lead she held on to for the duration.

An all-Slovene semifinal is on the cards up next, as Juvan will face top seed and defending champion Tamara Zidansek, who defeated No.7 seed Timea Bacsinszky, 7-6(5), 6-4.

Zidansek trailed by a break three times in the opening set, and saved two set points before ultimately opening up her lead against the former World No.9, and came through a second set which saw seven combined breaks of serve.

The second semifinal will see No.2 seed Sara Sorribes Tormo face No.4 seed Anna Karolina Schmiedlova.

The Spaniard dropped just one game in defeating No.8 seed Laura Siegemund, 6-1, 6-0, while Schmiedlova edged No.6 seed Jil Teichmann, 6-3, 6-4.