Unseeded Australian Open debutant Elise Mertens blew away world number four Elina Svitolina in straight sets Tuesday to reach a first Grand Slam semi-final.

The Belgian world number 37 knocked out the Ukrainian 6-4, 6-0 in 1hr 13min. She will face either second seed Caroline Wozniacki or unseeded Carla Suarez Navarro for a place in Saturday’s final.

She will head into the semi-final on a 10-match winning streak after defending her Hobart title on the eve of the Australian Open.

“I’m lost for words. I don’t know what to say. I just gave my all today,” she said. “I played my game today and tried to stay aggressive.”

Mertens, 22, trains with her coach and boyfriend Robbe Ceyssens at the Kim Clijsters Academy in Belgium and has seen her world ranking rise from 127 at the end of 2016.