Fonseca fights off Struff at Phoenix Challenger, reaches QFs

Joao Fonseca found his best level when he needed it most Thursday at the Arizona Tennis Classic, where he advanced to the quarter-finals. The #NextGenATP Brazilian fought off World No. 46 Jan-Lennard Struff 6-1, 4-6, 6-3, marking his eighth Top 50 win of his young career.

Fonseca, a two-time ATP Challenger Tour champion, made a flying start after rain slightly delayed the match start. The 18-year-old fed off Struff’s heavy hitting and created booming firepower of his own in chilly evening conditions. Fonseca dropped just two points behind his first serve in the opening set.

Final 8️⃣ feeling for Fonseca#ATPChallenger pic.twitter.com/C9rkfC50DP

— ATP Challenger Tour (@ATPChallenger) March 14, 2025

In the decider, Fonseca saved five break points across three different service games, according to Infosys ATP Stats, to secure the one-hour 41-minute win at the ATP Challenger 175 event.

“It was difficult to warm up today, a lot of rain. It’s cold outside, a little bit windy, so it was difficult to focus,” Fonseca said in his on-court interview. “I’m happy with the way that I fought today.”

Fonseca will next meet French lefty Hugo Gaston, who moved past Reilly Opelka 7-6(6), 6-3.

In other Phoenix action, Portugal’s Nuno Borges began his three-peat quest by overcoming Jacob Fearnley 6-2, 7-5. The top seed changed direction with ease and recovered a break deficit in the second set to reach the quarter-finals, extending his Phoenix winning streak to 11.

Up next for Borges is local favourite Colton Smith. A senior at the University of Arizona, the 22-year-old downed seventh seed Roman Safiullin 6-4, 7-6(2).

Second seed Flavio Cobolli ended his seven-match skid with a hard-fought 6-3, 5-7, 7-5 win against American wild card Eliot Spizzirri. Alexander Bublik also advanced in three sets, moving past Rinky Hijikata 6-2, 5-7, 6-3. Corentin Moutet defeated third seed Pedro Martinez 6-4, 6-3 and Kei Nishikori advanced after Mikhail Kukushkin retired with the Japanese star leading 6-3, 2-1.

Cap Cana
Top seed Alexandre Muller made a quick start to his Challenger 175 campaign, racing past Australian qualifier James McCabe 6-0, 6-2 at the Republica Dominicana Open, Copa Cap Cana Ciudad Destino.

“I’m very happy about the match today, I think I played great. It’s a little bit windy today, but I managed it well,” said Muller, No. 44 in the PIF ATP Rankings.

^{Alexandre Muller in action Thursday at the Cap Cana Challenger. Credit: Mike Lawrence/ATP Challenger Tour}

The 28-year-old will next face countryman Constant Lestienne, who ousted Fabio Fognini 6-4, 6-3. Lestienne has downed two consecutive former Top 10 players at the hard-court event, having defeated Cameron Norrie in the opening round.

Czech Jakub Mensik enjoyed smooth sailing, earning a 6-4, 6-2 win against fellow #NextGenATP player Rei Sakamoto. Mensik's quarter-final opponent will be Tomas Martin Etcheverry, the Argentine who defeated Nicolas Mejia 6-2, 6-4.

German Daniel Altmaier won the longest match of the day, surviving fourth seed David Goffin 6-2, 6-7(12), 6-3 after two hours, 46 minutes. Altmaier held four match points in the second-set tie-break before being pushed to a decider.

Firing all cylinders 💥@mensik_jakub_ dispatches Sakamoto 6-4, 6-2 to reach the final eight in Cap Cana #ATPChallenger pic.twitter.com/CBWOIG0knu

— ATP Challenger Tour (@ATPChallenger) March 13, 2025