Australian Open champion Aryna Sabalenka saw her 13-0 undefeated start to the season come to an end as she squandered a 6-0, 3-1 lead in a Dubai quarter-final defeat to Barbora Krejcikova on Thursday.But that streak was snapped as Krejcikova scooped a 0-6, 7-6(7/2), 6-1 victory to set up a semi-final clash with American No.3 seed Jessica Pegula.