Stan Wawrinka continued his damage comeback with a hard-fought win over Karen Khachanov to attain the quarterfinals of the St. Petersburg Open on Wednesday.
Wawrinka saved two set factors in every set on his approach to profitable 7-6 (10), 7-6 (1) over the fourth-seeded Khachanov, who at No. 24 is ranked 64 locations above Wawrinka.
Wawrinka’s quarterfinal opponent can be both defending champion Damir Dzumhur or Guido Pella.
Also Wednesday, fifth-seeded Roberto Bautista Agut beat qualifier Luca Vanni 7-5, 6-2 of their first-round match.
Canadian 19-year-old Denis Shapovalov, seeded seventh, gained 7-6 (three), 6-2 towards qualifier Adrian Menendez-Maceiras. He’ll meet Matteo Berrettini of Italy in the second spherical.