DELRAY BEACH, Fla. — American Mackenzie McDonald beat No. 1-seeded Juan Martin del Potro on Friday night in the quarterfinals of the Delray Beach Open, 6-4, 3-6, 7-6 (5).
McDonald, ranked 84th, advanced to his first ATP Tour semifinal. Del Potro was playing in his first event after missing four months because of a right knee injury.
No. 4 Steve Johnson of the United States squandered an early lead and lost to Radu Albot 1-6, 6-3, 7-6 (5). Albot will play McDonald on Saturday.
No. 2 John Isner hit 24 aces and won every service game to beat Adrian Mannarino 7-6 (2), 6-4. Isner improved his career record against the Frenchman to 7-1.
Isner’s opponent in the semifinals will be qualifier Dan Evans, ranked 148th, who swept No. 6 Andreas Seppi 6-4, 6-4.
NOTTINGHAM, England — Former champion Donna Vekic finally got to play on grass at the Nottingham Open on Friday but had to overcome multiple rain delays and another switch indoors before reaching the semifinals.
The second-seeded Vekic defeated Kristina Mladenovic 7-5, 6-4 in a match played on two surfaces as rain again played havoc with the schedule.
The opening two days were completely washed out before organizers decided to switch the first and second rounds indoors as rain fell for four consecutive days.
Vekic, who won the tournament in 2017, will play Germany’s Tatjana Maria in her third straight semifinal in Nottingham. Maria earlier defeated Ajla Tomljanovic 6-3, 7-6 (7) in the only match completed on grass so far at the tournament.
Also Friday, American Jennifer Brady defeated fourth-seeded Maria Sakkari of Greece 7-5, 6-3 to set up a semifinal against top-seeded Caroline Garcia.
Garcia rallied to beat Romanian qualifier Elena-Gabriela Ruse 4-6, 7-6, 6-1 in the last quarterfinal.
STUTTGART, Germany — Canadian teenager Felix Auger-Aliassime will play Italy’s Matteo Berrettini in the final of the Stuttgart Open.
The 18-year-old Auger-Aliassime progressed to his third tour-level final without playing on Saturday as compatriot Milos Raonic withdrew ahead of their semifinal due to back problems. The sixth-seeded Raonic lost last year’s final to Roger Federer, who opted not to defend his title.
Berrettini defeated Germany’s Jan-Lennard Struff 6-4, 7-5 in the other semifinal. The 30th-ranked Berrettini will be going for this third tour title and his first on grass after victories in Budapest in April, and Gstaad, Switzerland, last year.
The 21st-ranked Auger-Aliassime previously reached championship matches in Rio de Janeiro in February and the Lyon Open in May – both on clay.