Buse Upsets Defending Hamburg Open Champion Cobolli In First Round

Ignacio Buse, Hamburg Open
Ignacio Buse (photo: Witters/Bitpanda Hamburg Open)

HAMBURG/WASHINGTON, May 19, 2026 (by Michael Dickens)

Peru’s Ignacio Buse made his Bitpanda Hamburg Open debut a memorable one Tuesday afternoon in Germany’s second-largest city.

Playing at a career-high ranking of No. 57, Buse opened play on Centre Court at Rothenbaum Tennis Stadium in the ATP 500 event on red clay not only by becoming the third Peruvian man to record a main-draw win in in Hamburg this century after Luis Horna in 2004 and Juan Pablo Varillas in 2021. He merely took out the tournament’s defending champion, Flavio Cobolli of Italy, too – and looked convincing in doing so.

Over the course of their 91-minute first-round match, won by Buse, 6-2, 7-5, over the No. 4 seed Cobolli, the 22-year-old qualifier from Lima, Peru leveled his 2026 tour-level record at 8-8 by being the more composed and steadier player on the red-brick clay surface. He finished with 16 winners – including a confident third-shot forehand winner on match point – and faced no break points from the World No. 12 Cobolli.  Buse outpointed his opponent 65-54.

“I knew I could win,” Buse said during his on-court with ATP Media afterward. “The level is very similar and if I have a good day, I think I could compete. I tried to go out convinced, and it worked.

“I think I played very well. I was very comfortable. Flavio didn’t have a great match, but it’s difficult to play these matches against the top players. I’m very happy with the win, but I have to prepare for tomorrow now.”

Buse, who has now won 15 of his 16-tour level matches on clay and was a semifinalist on the surface at Santiago last February, is the first player from his country to defeat a Top-20 player on this surface since Varillas defeated No. 14 Hubert Hurkacz at Roland-Garros in 2023. It was just his third match against a Top-20 player, after defeating No. 20 Nicolas Jarry in the 2024 Davis Cup and losing to No. 6 Ben Shelton at the US Open last year.

Meanwhile, it was the second-straight defeat for Cobolli, who was knocked out of the Italian Open in the third round by Thiago Agustin Tirante of Argentina last week. In Cobolli’s fifth ATP Tour clay event this season, he had gone undefeated (4-0) in opening-round play until losing to Buse.

In the second round, Buse will face No. 28 Jakub Mensik of Czechia.

Top seed Auger-Aliassime advances

World No. 5 and top seed Felix Auger-Aliassime of Canada advanced to the second round with a solid 7-5, 6-1 victory over Vit Kopriva of Croatia in an hour and 25 minutes on Centre Court for his 19th victory of the season.

Auger-Aliassime, a semifinalist last year, hit 13 winners – including eight service aces – and saved all three break points he faced from the 63rd-ranked Kopriva, which came early in the first set. He converted three of four break points and outpointed Kopriva 63-43.

“Obviously, you must have a smile when you win,” Auger-Aliassime said during his on-court interview with ATP Media. “Every win matters; every win is important. I’m glad I was able to get the win today. I didn’t know my opponent and wasn’t sure what to expect. He’s had some good wins in the clay season, such as [Andrey] Rublev in Madrid. I told myself I needed to be ready for a high level from him.

“I thought it was very close in the first set and, then, I managed to break him in the right moments to be clutch. I think his level dipped a little bit in the second set and mine stayed high. I’m really happy overall with my performance.”

Next, Auger-Aliassime will face 94th-ranked American lucky loser Aleksandar Kovacevic, who advanced with a 6-2, 7-6 (3) win over qualifier Arthur Gea of France, ranked No. 140, in one hour and 41 minutes on M2 Court. Kovacevic outpointed Gea 73-58.

Altmaier prevails over Shelton

Tuesday’s last match on Centre Court featured No. 2 seed Ben Shelton of the United States, who came into his first meeting against the 65th-ranked German No. 3 Daniel Altmaier undefeated (11-0) at ATP 500 level this season. The 23-year-old from Florida attempted to become the first American men’s quarterfinalist in Hamburg since Andre Agassi and Pete Sampras in 1995.

However, Altmaier recovered from a shaky start and handled the pressure moments in the final set better than Shelton. By the end of the two-hour, 50-minute second-round tussle, it was Altmaier who prevailed, 4-6, 7-6 (4), 6-4, to advance to the last eight. Shelton had become the second seeded player to bow out of the tournament, following No. 4 seed Flavio Cobolli.

Altmaeier, who looked to gain his second quarterfinal berth in Hamburg after 2023, looked ripe for a straight-set loss. However, he broke Shelton, who was attempting to serve for the match, in the 10th game of the second set. It seemed to lift Altmaier’s spirit and he went on from the 5-all deadlock to win the second set in a tie-break, 7-4, which sent the second-round match into a decider.

As the third set unfolded, Altmaier saved four break points and held serve to win an 18-point second game that stretched across 12-plus minutes for 1-all. Soon, Altmaier broke to go ahead 3-2 after striking a sixth-shot forehand winner. He backed up the break for a 4-2 lead, then gained a break point at 30-40 against Shelton in the sixth game. However, the American No. 1 saved it with an overhead smash winner, then saved three additional break points before gaining a vital hold during another lengthy 18-point game.

“It was a crazy comeback,” Altmaier said during his on-court interview with ATP Media. “I think I’m proud of coming back from a set and 4-5 down. I felt I played quite well but I’m glad to go through in the end.”

Next, Altmaier held solidly for 5-3, needing just one more service hold to upset Shelton and move into the quarterfinal round. Soon, looking for his fifth career Top-10 triumph on clay, the 27-year-old Kempen native rose to the occasion and put away his biggest victory of the season – his sixth win of 2026 – on his first match-point after Shelton sailed a second-shot forehand long and wide.

 

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By the conclusion, Altmaier had won 71 percent (42 of 59) of his first-serve points, hit 34 winners to 24 unforced points – compared to 47 winners and 43 unforced errors by Shelton – and converted three of 11 break points. He outpointed Shelton 110-107.

Altmaier (6-13 this season at tour level) will face either No. 6 seed Tommy Paul of the United States or No. 25 Tomas Martin Etcheverry of Argentina. Their second-round match on M1 Court Tuesday evening was suspended by darkness just before 9 p.m. local time, tied at a set each, and will be resumed on Wednesday. 

Etcheverry won the opening set in a tie-break 7-5 and the World No. 26 Paul leveled the match by winning the second set in a tie-break 7-5.

Around Rothenbaum Tennis Stadium

• Eighteen-year-old German wild card Justin Engel from Nürnberg, who was making his second appearance at the event, aimed to become the fourth German man to earn multiple wins in Hamburg before turning 19. Ranked No. 190, Engel entered his first-round match against No. 34 Ugo Humbert of France 1-3 against Top-50 opponents, defeating No. 35 Alex Michelsen in Stuttgart last year.

On Tuesday, Engel sought the biggest win of his nascent career against Humbert, who had compiled a 12-1 record versus players ranked outside the Top 100 since September 2024. He aimed to break a nine-match losing streak against German players and to earn his first win since defeating Alexander Zverev at Halle in 2021.

As it happened, Engel pushed Humbert to three sets before the 27-year-old Frenchman prevailed, 6-3, 3-6, 7-6 (2), in two hours and 21 minutes on Centre Court. Each player was broken just once, but by the conclusion Humbert outpointed Engel 106-97 to collect his 14th tour-level win of the season.

Next Humbert will face No. 5 seed Karen Khachanov of Russia, who needed to go the distance to defeat 120th-ranked lucky loser Hugo Gaston of France, 3-6, 6-3, 7-6 (4), in two hours and 38 minutes on M1 Court. Khachanov, who outpointed Gaston 104-100 in their first meeting.

• No. 7 seed Luciano Darderi of Italy, playing in his first match since losing in the semifinal round last Friday at Rome, defeated No. 66 Roman Andres Burruchaga of Argentina, 6-3, 7-6 (4), in one hour and 49 minutes on M1 Court. Darderi hit 23 winners and outpointed Burruchaga 80-71 in their first tour-level meeting. Next, the World No. 16 Darderi will face No. 55 Yannick Hanfmann of Germany, one of only two German players remaining in the singles main draw.

• In doubles, No. 1 seeds Julian Cash and Lloyd Glasspool of Great Britain advanced to the quarterfinal round with a 6-4, 3-6, 10-7 victory over qualifiers Fernando Romboli of Brazil and Ryan Seggerman of the United States. 

Also, No. 3 seeds Kevin Krawietz and Tim Puetz of Germany advanced to the quarterfinals after defeating Hugo Nys of Monaco and Edouard Roger-Vasselin of France, 6-4, 7-6 (5). German wild cards Jakob Schnaitter and Mark Wallner advanced with a 2-6, 6-3, 10-8 comeback victory over Francisco Cabral of Portugal and Joe Salisbury of Great Britain, while another pair of German wild cards, Hendrik Jebens and Tim Ruehl, fell to French duo Theo Arribage and Albano Olivetti, 6-4, 3-6, 10-7.

Tuesday’s Hamburg Open results

Wednesday’s Hamburg Open order of play

By the numbers

When Ignacio Buse of Peru upset defending Hamburg Open champion Flavio Cobolli in the first round on Tuesday, it was the seventh time since 2000 that a defending champion had lost in the opening round in Hamburg.

“Quotable …”

“It was really not an easy match. [Justin] is really young, he’s really good and plays so fast from the baseline – especially his backhand. It was not easy to manage him from the baseline. I’m super happy I could win this match in a tie-break the last set.”

– No. 34 Ugo Humbert of France, during his on-court interview with ATP Media, after defeating 190th-ranked German wild card Justin Engel in three sets.

 

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