Zhang Shuai has set up a Mexican Open semi-final with top seed Dominika Cibulkova by battling past Ajla Tomljanovic in three sets in Acapulco.
The world number 50 stormed into a one-set lead as Tomljanovic failed to hold serve once in the opener, which she lost 6-1.
Zhang then moved 3-1 ahead in the second set after Tomljanovic missed five break point opportunities in a fourth game that went to deuce on five occasions.
However, the 20-year-old broke twice later in the set to take it 7-5 and level the match.
Her habit of starting sets slowly continued in the decider though, as Zhang, who has never got past the opening round of a Grand Slam in nine outings in the main draws, won four games in a row en route to securing a 6-1 5-7 6-1 win in just shy of two hours.
