(Photo credit: David Gonzales-Imagn Images)

Czech rising star Jakub Mensik hit 11 aces and rode a dominant third set to a 7-6 (3), 2-6, 6-3 upset of No. 2 seed Jannik Sinner of Italy at the Qatar ExxonMobil Open quarterfinals on Thursday in Doha.

The sixth-seeded Mensik won 14 of his 16 first-service points in the third set and 49 of 60 overall (81.7%) while saving 5 of 7 break points in the match. Sinner, who fell in the semifinals of the Australian Open, missed the final in back-to-back starts for the first time since the summer of 2024.

No. 1 seed Carlos Alcaraz of Spain now has a clearer path to the title at the ATP 500 event, though he survived a scare of his own in the quarterfinals when he rallied past Russian seventh seed Karen Khachanov 6-7 (3), 6-4, 6-3. Alcaraz had a 41-14 edge in winners to overcome his 34 unforced errors.

Alcaraz's semifinal opponent will be No. 5 seed Andrey Rublev of Russia, a 6-3, 7-6 (2) winner over Greece's Stefanos Tsitsipas. Mensik will battle Frenchman Arthur Fils, who upset Czech eighth seed Jiri Lehecka 6-3, 6-3.

Delray Beach Open

No. 4 seed Learner Tien hit 20 aces among his 51 winners to fight past Serbia's Miomir Kecmanovic 6-4, 6-7 (4), 7-6 (5) in Delray Beach, Fla.

Kecmanovic saved four match points -- one in the 12th game to force a tiebreaker, then three more after going down 6-2 -- but he could not save a fifth. Tien's quarterfinal opponent, No. 8 seed Frances Tiafoe, also needed three sets to turn back qualifier Zachary Svajda 6-4, 3-6, 7-5, saving 5 of 6 break points along the way.

The evening matches in Florida pit No. 5 seed Tommy Paul against Australian Adam Walton and No. 1 seed Taylor Fritz against Spain's Rafael Jodar.

Rio Open

Portuguese lucky loser Jaime Faria kept his week going by beating Bosnia and Herzegovina's Damir Dzumhur 7-6 (1), 6-4 to advance to the quarterfinals in Rio de Janeiro.

Faria, who hit 26 winners and had to get past 29 unforced errors, is joined in the next round by No. 8 seed Tomas Martin Etcheverry of Argentina, who defeated Lithuanian qualifier Vilius Gaubas by an identical 7-6 (1), 6-4 scoreline.

The late matches in Rio see third-seeded Joao Fonseca of Brazil take on Peru's Ignacio Buse and Italian Matteo Berrettini oppose Serbian lucky loser Dusan Lajovic.

--Field Level Media