Botic van de Zandschulp is the only seeded player remaining at the Winston-Salem Open, advancing to the semi-final after winning a pair of tiebreakers against Benjamin Bonzi 7-6 (8-6) 7-6 (7-1).

Van de Zandschulp, the second seed, is yet to lose a set in the tournament after straight sets wins against Tallon Griekspoor and Jaume Munar, and he used his dominant serve to get the job done against France's Bonzi.

The Dutchman had 15 aces while Bonzi had three, and he posted 50 winners to Bonzi's 24 in a terrific exhibition of power tennis.

Van de Zandschulp, 26, will face Adrian Mannarino in the semi-final as the 34-year-old seeks his second career ATP Tour title, beating Maxime Cressy 6-4 7-6 (7-3).

Fourth seed Cressy was Mannarino's third consecutive seeded scalp, having also defeated ninth seed Emil Ruusuvuori and eighth seed Albert Ramos-Vinolas to make it this far.

Cressy's 10 double faults and 26 unforced errors shot himself in the foot, as the veteran Mannarino played a clean match, posting two double faults and eight unforced errors.

Serbia's Laslo Djere has taken the scenic route to the semi-final, winning his fourth three-set match of the week as he edged past Richard Gasquet 6-4 3-6 7-6 (8-6) in two hours and 43 minutes.

It comes after a three-hour-11-minute marathon against Jason Kubler in the previous round, and a two-hour-50-minute war of attrition against Joao Sousa prior to that.

Djere will hope to have some more gas in the tank when he meets Switzerland's Marc-Andrea Huesler in the semi-final after he upset 13th seed Jack Draper 6-4 6-4.