SAN JOSE, Calif. (AP) Maria Sakkari of Greece upset third-seeded Venus Williams 6-4, 7-6 (2) on Friday night in the quarterfinals of the Mubadala Silicon Valley Classic.
Sakkari came back from 0-3 in the first set and 3-5 in the second set. She advanced to face American Danielle Collins – with the winner reaching her first WTA final.
Collins, a two-time NCAA champion for Virginia, advanced after former world No. 1 Victoria Azarenka of Belarus retired midway through the second set due to injury.
Azarenka led 4-2 in the first set before needing a tiebreaker to win the 72-minutes set 7-6 (4). She grabbed her right leg in the opening game of the second set, lost the first three games and was evaluated by a trainer and doctor before retiring prior to the fourth game.
Fifth-seeded Mihaela Buzarnescu of Romania secured the first semifinal spot by beating Australia’s Ajla Tomljanovic 6-1, 7-5. The Romanian will face No. 4 seed Elise Mertens.
Mertens, a Belgian, saved two set points in the first set, forced a tiebreak and won four straight games in the second set for a 7-6 (4), 6-3 victory over Johanna Konta. It’s Mertens’ fifth WTA semifinal of the year.
STUTTGART, Germany — Matteo Berrettini beat Canadian teenager Felix Auger-Aliassime 6-4, 7-6 (11) to win the Stuttgart Open and his third tour-level title on Sunday.
The Italian saved five set points in a second-set tiebreaker and clinched his first title on grass. His other titles came at Budapest in April, and Gstaad, Switzerland, last year.
The 18-year-old Auger-Aliassime previously reached championship matches in Rio de Janeiro in February and the Lyon Open in May – both on clay.
Berrettini won all 50 of his service games during the week in Stuttgart. He did not face a break point against Auger-Aliassime.
Auger-Aliassime progressed to the final in his first professional grass tournament without playing Saturday as compatriot Milos Raonic withdrew ahead of their semifinal due to back problems.
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.