Novak Djokovic cast off concerns over his form and mindset by easing to a 6-1 6-2 6-4 win over Diego Schwartzman in the first round of the US Open.
Since winning Wimbledon, the world number one has had off-court matters on his mind, with marriage to long-term partner Jelena to be followed in October by the birth of their first child.
He made a decidedly sluggish start to the North American hard-court season and arrived in New York with not many matches under his belt after losing early in Toronto and Cincinnati.
But Djokovic was quick to show Argentinian Schwartzman who was boss under the lights on Arthur Ashe, racing into a 4-0 lead.
Schwartzman clearly wanted to make the most of the occasion and urged the crowd to raise the noise level after a precision lob and forehand winner helped him get on the board with a break of the Djokovic serve.
It was merely a blip, though, and 79th-ranked Schwartzman did not win another game until he was 2-0 down in the second set, finally holding serve for the first time.
The precision on Djokovic's shots was far too good for his opponent, highlighted by a forehand winner hit round the net post to gasps and cheers.
Schwartzman is much more at home on clay than hard courts but made a better fight of things in the third as Djokovic's level dropped.
The Serbian was never in any danger, though, and served out victory after an hour and 37 minutes, the final act a rather fortunate net cord.
Djokovic, who next plays France's Paul-Henri Mathieu, said: "I'm very pleased. It's never easy to start a US Open smoothly. I love playing night sessions, it's probably the most special court in the world for night sessions."