Both first-round and second-round action will be part of Tuesday’s schedule at the Hamburg ATP 500. Flavio Cobolli gets underway against Ignacio Buse, while Ben Shelton faces Daniel Altmaier for a spot in the quarterfinals.
(4) Flavio Cobolli vs. (Q) Ignacio Buse
Cobolli is looking to bounce back from a second-round loss at the Rome Masters when he takes the court in round one of the Hamburg Open on Tuesday. A straight-set ouster in front of the home crowd at the hands of an in-form Thiago Agustin Tirante certainly wasn’t ideal for Cobolli, but at least it means he is will rested for this week. The 12th-ranked Italian has mostly been good on this clay-court swing, with a runner-up performance in Munich and a quarterfinal showing in Madrid.
Up first for Cobolli is Buse, whom he has never faced. It has been a breakthrough 2026 campaign for Buse, who has almost doubled his previous main-tour win total (seven this season, 15 overall). The 22-year-old Peruvian is up to No. 57 in the world thanks in part to a semifinal run on the red clay of Rio de Janeiro. Tennis stats for daily analysis and predictions will confirm that Buse is firmly on the rise. This is a dangerous matchup for Cobolli because Buse is a clay-court specialist and already has two qualifying wins under his belt in Hamburg. Still, the fourth seed should advance.
Pick: Cobolli in 3
Daniel Altmaier vs. (2) Ben Shelton
Shelton took the scenic route to the second round, outlasting fellow American Marcos Giron 6-3, 4-6, 7-6(3) on Monday. It was a much-needed result for the world No. 6, who beat Cobolli for the Munich crown last month but then lost his opening matches in both Madrid and Rome — in tight three-setters against Dino Prizmic and Nikoloz Basilashvili, respectively.
Standing in Shelton’s way of the quarters is Altmaier, and they will also be going head-to-head for the first time in their careers. Altmaier kicked off his week with a 7-5, 6-2 victory over Rinky Hijikata, giving him at least one win at six of his last eight tournaments. The 65th-ranked German may not be on fire, but he is at least playing much better than he was earlier in the year — not surprising since Altmaier has always his best work on clay. Given home-court advantage for the underdog and Shelton’s unconvincing current form on a surface that really isn’t ideal for his game, an upset could be in the cards.
Pick: Altmaier in 3