Jakub Mensik defeated Jannik Sinner 7-6, 2-6, 6-3, in the quarterfinals of the Qatar Open.
The Czech youngster delivered a remarkable serving display to stun the world number two in Doha.
Mensik was excellent in the first and third sets as he picked up the biggest win (by ranking) of his professional career.
Is it time to start worrying about Jannik Sinner yet?
He has not looked himself in 2026…
During his post-match interview, Mensik shared his thoughts on Sinner.
Jakub Mensik says Jannik Sinner is a ‘great guy’ after beating him in Doha
The 20-year-old only had nice things to say about Sinner after the match.
“Before the match, I knew about Jannik’s qualities,” said Mensik.
“He’s a great guy. A great champion.
“Already, what he’s done in his young career is pretty impressive.”
Mensik respected Sinner’s qualities, but approached the match with a winning mentality.
“I knew it was going to be a tough one,” he said.
“But even with that thought, I came to the match to win it.
“Actually, having a winning mindset.
“I served pretty well, even if the conditions were starting to get slower during the night.
Jakub Mensik vs Jannik Sinner – Match stats
| Stats | Jakub Mensik | Jannik Sinner |
| Aces | 11 | 6 |
| Double faults | 4 | 1 |
| 1st Serve % | 71% | 63% |
| Win % on 1st Serve | 82% | 72% |
| Win % on 2nd Serve | 43% | 66% |
| Break points | 2/4 | 2/7 |
“It was a very, very tough mental battle.”
Mensik was proud of the way he recovered after a tricky second set.
“After the second set, I dropped my energy a little bit. I’m really happy [with how] I came back after the toilet break,” he said.
“From the beginning of the third set, I just started to serve well again.
“I’m just happy with the performance I showed today.”
Mensik can be very pleased with his efforts in Doha, but the same can’t be said for his opponent…
What’s going on with Jannik Sinner?
It’s probably not time to panic yet, but this isn’t the Sinner we’re used to, that’s for sure.
The Italian lost at the Australian Open for the first time since 2023 last month, and has now suffered another shock defeat, this time at the hands of the world number 16.
Sinner isn’t playing badly, of course not, but he’s looked a lot better.
He mentioned that he was struggling from the baseline earlier this week, and perhaps that’s an area he needs to focus on.
Whatever the problem is, he needs to find a solution, and fast, or he’ll continue to lose ground to Carlos Alcaraz in the race for number one.
Sinner hasn’t held the top spot since November and currently trails Alcaraz by just under 3,000 points.
Official ATP Rankings
- 1. Carlos Alcaraz – 13,150 points
- 2. Jannik Sinner – 10,300 points
- 3. Novak Djokovic – 5,280 points
- 4. Alexander Zverev – 4,605 points
- 5. Lorenzo Musetti – 4,405 points
Many had backed Sinner to return to world number one this year, having missed this ‘section’ of the season in 2025 due to suspension.
With no points to defend between now and the Italian Open, Sinner, if he were playing his best tennis, would be expected to pick up a few titles and plenty of points, closing the gap to Alcaraz in the process.
But this version of Sinner may struggle to do that.
Two defeats won’t define his season, though, and he and his team will know that.
Has anyone in tennis history ever hit the ball as hard as Jannik Sinner does?
The events keep coming, and he’ll have a chance to redeem himself before too long.
And at tournaments he’s excelled at, no less.
Sinner is a two-time semifinalist at Indian Wells and a former Miami Open champion.
If he can repeat those results next month, then he’ll be right back on track.
Who plays who in the Qatar Open semifinals?
We know that Sinner won’t join Mensik in the last four, but who will?
- SF 1 – [1] Carlos Alcaraz vs [5] Andrey Rublev
- SF 2 – Arthur Fils vs [6] Jakub Mensik
Alcaraz will play Rublev in the first semifinal, before Mensik takes on the in-form Arthur Fils.
Fils and Mensik have met twice before, once at the 2024 Next Gen Finals and once at the 2025 Miami Open.
The Frenchman won their first encounter before Mensik leveled their head-to-head in Miami.
After beating Fils, Mensik went on to win the Miami Open.
Only time will tell if history repeats itself in Doha.
Mensik and Fils will contest their semifinal match on Friday, February 20.
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