Novak Djokovic will replace young rival Carlos Alcaraz as the men's world number one after a routine win on his US Open return.
Serbia's Djokovic, who lost the Wimbledon final to Alcaraz, won 6-0 6-2 6-3 against France's Alexandre Muller in Monday's night session in New York.
Djokovic, 36, was not allowed to play in the United States last year because he was not vaccinated against Covid-19.
He has returned knowing another title will be a record-equalling 24th major.
Matching Australian Margaret Court's all-time tally is Djokovic's target and he made a statement start by breezing past 84th-ranked Muller.