World number five Aryna Sabalenka was made to toil by Liudmila Samsonova before the Belarusian sealed a 7-6(8) 7-6(3) victory that secured her place in the quarter-finals of the Adelaide International 1 WTA 500 tournament on Wednesday. Having received a bye into the second round, second seed Sabalenka started sluggishly to find herself in trouble trailing by five games to one but the 24-year-old roared back to save six set points and claim the opening set in the tie-break.