Twelve months after he was deported as a risk to public health because of his refusal to receive the Covid-19 vaccine, Djokovic has returned to the country following the decision to overturn his visa ban.
His first match was a low-key doubles encounter alongside close friend Vasek Pospisil, which the pair lost 4-6 6-3 (10-5) to Bosnian Tomislav Brkic and Ecuador's Gonzalo Escobar.
But any fears Djokovic may have had about how he would be received by the public were swiftly allayed as his supporters flocked to Memorial Drive to welcome him back.
Djokovic begins his singles campaign on Tuesday against Frenchman Constant Lestienne as he builds up to the Australian Open, where he is looking for a record-extending 10th title.
There were two shocks in singles action on Monday, with second seed Felix Auger-Aliassime losing 6-4 7-6 (5) to Australian Alexei Popyrin while fifth seed Holger Rune was beaten 2-6 6-4 6-4 by Japan's Yoshihito Nishioka.