Alexander Zverev suffered a disappointing start to his reign as world No. 1 after losing 7-6(5), 6-2 to Italy's Lorenzo Musetti in the second round of the Paris Masters on Wednesday.
The German, who officially claimed the top spot in the ATP rankings on Monday, struggled to find his rhythm against the in-form Musetti, who secured the victory in straight sets to advance to the last 16.
Zverev had an opportunity to take control of the opening set after building a 5-2 lead in the tie-break. However, Musetti fought back brilliantly, winning five consecutive points to take the set and gain the upper hand.
The Italian carried that momentum into the second set, taking advantage of Zverev's growing number of unforced errors to secure two breaks of serve and close out the match.
Despite the defeat, Zverev insisted that the pressure of becoming world No. 1 was not responsible for his performance. Instead, the 29-year-old admitted he was frustrated by the criticism surrounding his rise to the top of the rankings.
"Achieving the world No. 1 status is something that I think every player dreams of. But then I feel like I'm the only world No. 1 in tennis history that has to explain why it's okay for me to be world No. 1, which I find quite difficult," Zverev said.
He added that he believed he deserved his position despite the questions raised about his achievement.
Zverev also accepted responsibility for his performance, admitting that Musetti was the better player on the day.
"To simplify it, he played really good and I played really bad," he said, describing the match as potentially one of his worst performances in recent months.
Musetti, meanwhile, was delighted with the victory, revealing that staying composed after falling behind in the opening-set tie-break was key to his comeback. The Italian also praised his ability to enjoy the match regardless of the score.
The defeat marked an unexpected setback for Zverev, who has enjoyed an outstanding 2026 season, winning his first two Grand Slam titles at the French Open and US Open. He also became the 30th player in ATP history to reach the world No. 1 ranking.
Elsewhere at the Paris Masters, Novak Djokovic suffered an unexpected second-round exit after losing to Australia's Rinky Hijikata 2-6, 6-3, 6-3. The defeat ended the Serbian's hopes of qualifying for the ATP Finals, leaving only two spots available for the season-ending tournament in Turin.
