Second seed Carlos Alcaraz defeated 35th-ranked American Alex Michelsen in their round-of-32 match at the ATP Paris Masters in Nanterre. (EPA Images pic)PARIS: Alexander Zverev said he was "annoyed" at having to justify being world No 1 as he lost his opening match at the Paris Masters, while 24-time Grand Slam champion Novak Djokovic also fell on a Wednesday full of upsets.

Carlos Alcaraz avoided a similar fate, however, as the seven-time major winner beat Alex Michelsen 7-6 (7/4), 6-3 to get his campaign off to a safe start.

Long seen as tennis' nearly-man, 29-year-old Zverev broke his major duck this year by winning the French and US Opens, which propelled him to the top of the ATP rankings for the first time in his career this month.