Novak Djokovic won his first match at the US Open since 2021.
The win secured Djokovic's return to No. 1 in world rankings.
Djokovic missed last year's tournament because of a vaccine mandate.
Djokovic said he was excited to be back in New York and playing at the US Open.
He said he felt no pressure despite not playing in the tournament for two years.
Djokovic defeated Alexandre Muller in straight sets.
He improved to 17-0 in first-round matches at the US Open.
Djokovic's win assured him he would regain the No. 1 ranking next month.
He said he was pleased with his performance and hoped to maintain his level of play.
Djokovic said he loves playing at the US Open and enjoys the atmosphere.