Mensik Stuns Sinner at Doha Open, Reaches Semifinals

20-year-old Jakub Mensik defeats world No. 2 Jannik Sinner in a major upset at the Qatar ExxonMobil Open.

Feb. 28, 2026 at 8:15pm

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In a stunning upset at the Qatar ExxonMobil Open, 20-year-old Jakub Mensik defeated world No. 2 Jannik Sinner 7-6 (3), 2-6, 6-3. The victory marks the biggest of Mensik's career and signals a potential changing of the guard in the world of men's tennis.

Why it matters

Mensik's victory over Sinner demonstrates his ability to perform on the big stage and against top-ranked opponents, suggesting a rising trajectory in the ATP rankings. Meanwhile, Sinner's unexpected struggles in the match represent a setback in his quest to emulate the success of rival Carlos Alcaraz.

The details

Mensik attributed his success to a strong serve and mental fortitude, particularly in the decisive third set. Sinner acknowledged making unexpected errors, particularly off his forehand. This defeat represents the first time Sinner has lost a completed hard-court match to a player outside the top 10 since October 2023, and it halted his streak of reaching finals at successive events since the summer of 2024.

  • Mensik previously upset Andrey Rublev during a run to the championship match in Doha in 2025.
  • Sinner had a three-month doping ban a year ago, ending in May.

The players

Jakub Mensik

A 20-year-old tennis player who has emerged as a rising talent on the ATP Tour, with the ability to defeat top-ranked opponents like Jannik Sinner.

Jannik Sinner

A world No. 2 tennis player who was aiming to emulate the success of rival Carlos Alcaraz at the Qatar ExxonMobil Open, but suffered an unexpected defeat to Jakub Mensik.

Carlos Alcaraz

A rising star in men's tennis, who continued his dominant start to the 2026 season by defeating Karen Khachanov in the Doha tournament.

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What they’re saying

“We must not let individuals continue to damage private property in San Francisco.”

— Robert Jenkins, San Francisco resident

“Fifty years is such an accomplishment in San Francisco, especially with the way the city has changed over the years.”

— Gordon Edgar, grocery employee

What’s next

Both Sinner and Alcaraz will now focus on the Sunshine Double – Indian Wells and Miami – next month. These tournaments will be crucial for both players as they strive to close the gap in the rankings and establish dominance in the early stages of the season. Mensik will also look to build on his momentum and continue his ascent in the ATP rankings.

The takeaway

Mensik's victory is part of a broader trend of young players challenging the established order in men's tennis. This influx of latest players suggests a more competitive and unpredictable future for the sport.