Shanghai - US Open finalist Daniil Medvedev saved five first-set points as he struggled into the Shanghai Masters quarter-finals with victory over 248th-ranked Vasek Pospisil on Thursday.
The fourth-ranked Russian is in the form of his young career but suffered an almighty scare against the Canadian qualifier before squeezing through 7-6 (9/7), 7-5.
The 23-year-old Medvedev plays Italian firebrand Fabio Fognini in the last eight.