Alexander Zverev's run as world No. 1 got off to a rough start.

Italy's Lorenzo Musetti beat the German 7-6 (5), 6-2 in the second round of the Paris Masters on Wednesday. It was Zverev's first match since he took over the top ranking on Monday.

"I was bad. It's quite simple," Zverev said. "This was not a very good match for me, I think maybe one of the worst in the last couple of months."

Musetti takes over

Musetti closed the match with an ace. He hit 29 winners to 25 for Zverev. He also made just 12 unforced errors to Zverev's 21.

"It was really close. It could have gone both ways," Musetti said. "The key was to stay there at 5-2. I played five great points in a row."

Zverev said the very fast indoor court should have suited his game.

Frustrated at the top

The 29-year-old won the first two Grand Slam titles of his career this year at the French Open and US Open.

He said he was "a bit annoyed" that he does not get enough credit. "I feel like I'm the only world No. 1 in tennis history that has to explain why it's OK for me to be world No. 1," he said.

Fils books his ticket

Frances Tiafoe wasted four match points in a 6-3, 1-6, 7-6 (9) loss to Frenchman Quentin Halys.

That result sent Arthur Fils to the ATP Finals in Turin from Nov. 15 to 22. He is the first Frenchman to make the event since Gael Monfils in 2016.

Fourth seed Daniil Medvedev lost 6-4, 6-4 to Ignacio Buse. Alex de Minaur and Learner Tien also went out in straight sets, while Tommy Paul beat Daniel Merida 6-1, 6-1.