World No.1 Novak Djokovic has turned the page on his contentious US Open default and begun his clay-court season with a convincing victory in the second round of the Rome Masters.

The top-ranked Serb was mostly courteous with the chair umpire during a 6-3 6-2 win over local wildcard Salvatore Caruso on Wednesday.

When the umpire came down to inspect a ball mark on the red clay early in the first set and made an overrule in Caruso’s favour, Djokovic just replied, “Yup,” and rubbed out the mark with his red sneaker.

When Caruso impressed him – the Italian hit 13 winners to Djokovic’s 12 – the Serb said, “Bravo.”

Djokovic’s only testy moment came during the third game of the second set, which went to deuce seven times before Djokovic finally broke Caruso’s serve.

As the game wore on, Djokovic appeared bothered by crowd noise, even though the Campo Centrale is empty of fans this year because of the coronavirus pandemic.

The only people inside the stadium were coaches and others working at the tournament.

“Which ones?” the umpire asked Djokovic, trying to figure out who was bothering him.

Djokovic replied curtly: “There’s 10 people in the stands.”

On Monday, Djokovic said that he had learned “a big lesson” after he was thrown out of the US Open 10 days ago for unintentionally hitting a line judge in the throat with a ball.

Djokovic, a four-time champion in Rome and chasing a record 36th ATP Masters 1000 title, next faces Italian qualifier Marco Cecchinato or Filip Krajinovic.

Nine-time Rome champion Rafael Nadal was to make his return to competition in Wednesday’s evening match after a seven-month absence against Pablo Carreno Busta.

Also in the second round, Rome resident and fourth-seeded Matteo Berrettini defeated Argentina Federico Coria 7-5 6-1 while Marin Cilic beat sixth-seeded David Goffin 6-2 6-2.

The clay-court event – which was rescheduled from May because of the pandemic – is an important warm-up for the rescheduled French Open, which starts on September 27.