Seven-time Grand Slam champion Carlos Alcaraz was unexpectedly defeated 7-5, 7-6 (4) by unseeded Belgian Zizou Bergs in the round of 32 at the Rolex Shanghai Masters on Monday. The result not only marked a significant upset but also secured Alexander Zverev’s position as the ATP’s year-end world No. 1.

Alcaraz, the tournament’s second seed, was coming off a Japan Open title defense and had recently returned from a wrist injury that sidelined him for nearly five months. However, he struggled to find his rhythm during the two-hour, two-minute contest, making numerous unforced errors and failing to establish a strong return position. He acknowledged his below-par performance after the match, crediting Bergs for serving well and expressing disappointment at his own inconsistency.

Bergs, 27, delivered a composed all-court performance, adapting well to the fast playing conditions. He broke Alcaraz’s serve three times and held his nerve in the crucial moments, including the tiebreak in the second set. Having lost their only previous meeting at last year’s Japan Open, Bergs showed no signs of intimidation and expressed relief at securing his biggest career victory, stating the experience had helped him raise his standard of play against top competitors.

The Belgian will face American Tommy Paul in the next round, who advanced after defeating defending Shanghai Masters champion Valentin Vacherot 6-4, 6-2.

Alcaraz’s early exit at the Masters 1000 event mirrors a series of high-profile early departures, including 24-time Grand Slam winner Novak Djokovic and US Open runner-up Ben Shelton.

Zverev’s ascension to the top of the ATP rankings was confirmed as a direct consequence of Alcaraz’s defeat. The German, 29, who won both the French Open and US Open titles this season, described finishing the year as No. 1 as a "dream come true," especially in light of his comeback from a career-threatening ankle injury sustained during the 2022 French Open semifinals.

This marks Zverev as the first German male player to conclude a season ranked No. 1 in the world, as well as the oldest player to claim the year-end top spot. The award is set to be presented in November. Germany’s Angelique Kerber and Steffi Graf have previously finished seasons as the No. 1-ranked women.

Zverev’s achievement coincides with a season marred by injuries to other leading players. Italy’s Jannik Sinner, the current world No. 1, has not played since his Wimbledon victory over Zverev and recently announced his season’s end due to a knee injury. Alcaraz, ranked third, missed several months between April and the US Open due to his wrist injury.

Zverev, who comes from a tennis family with parents who competed at a high level in the former Soviet Union, remains a controversial figure due to domestic violence allegations made by two former partners. He has consistently denied these claims. An ATP investigation into one allegation found insufficient evidence to sanction him, while a separate 2023 German court case resulted in a penalty and fine but was later dropped following a settlement reached in June 2024 just hours before he was due to compete in the French Open semifinals.