Zizou Bergs claimed the biggest win of his career as he defeated Carlos Alcaraz, handing Alexander Zverev the year-end number one in the process.

Having triumphed in Tokyo last week, Alcaraz looked poised for a deep run at the Shanghai Masters.

Instead, Bergs claimed a stunning 7-5 7-6 (7-4) victory to send the world number three packing.

It is just Bergs' third career win in 17 matches against ATP top 10 opponents, and his second of 2026 after defeating Felix Auger-Aliassime at the United Cup.

"I often have too much respect for these guys, which is part of my culture and I'm proud of that," said Bergs of claiming such a huge scalp.

"But it gets a little bit in the way when you have to play them. I had a great moment here last year against [Novak] Djokovic where I was definitely playing the name, not the guy.

"The more experience you have practising against them and playing matches, the more it becomes the new standard a little bit. To have this moment, it is a little bit of a relief. I feel like now I really can win against these guys. Not just I can play against them, but I can win against them."

Bergs was largely flawless until he was serving for the match at 5-4 up in the second set.

At that stage, the nerves appeared to set in, and Alcaraz broke to force a tie-break.

Another wobble saw Bergs let a lead slip as Alcaraz levelled at 4-4, but the Belgian then reeled off three straight points to clinch a memorable victory.

Arthur Fils and Taylor Fritz were big-name exits on Monday, while Daniil Medvedev, Casper Ruud, Auger-Aliassime and Rafael Jodar all progressed.

Sascha’s year @AlexZverev clinches ATP Year-End No. 1 presented by PIF honours, the first German to do so https://t.co/9Vhzyywvzu

— ATP Tour (@atptour) October 12, 2026

Zverev's maiden year-end crown

Alcaraz's defeat means Zverev is now sure of ending 2026 as the world number one in the ATP rankings.

Zverev, a two-time grand slam champion this year, is the first German to achieve the feat.

At the age of 29 years and 217 days when the final rankings are published next month, Zverev will be the oldest player to claim the year-end number one for the first time.

Andre Agassi was 29 years and 214 days old when he did so in 1999 and Andy Murray was 29 years and 197 days old in 2016.

Zverev becomes the fourth active player to earn the year-end number one spot, after Novak Djokovic (eight times), Alcaraz (two times) and Jannik Sinner (once).

"It's been a fantastic season for me winning in Paris and New York and knowing that I will finish the year on top of the rankings is just a dream come true," Zverev said.

"So much work and effort have been put into achieving this goal, especially after coming back from the ankle injury. I look forward to finishing the season in style."