Novak Djokovic hailed Dino Prizmic as a future star after his narrow 6-2, 6-7 (5), 6-3, 6-4 win against the 18-year-old Croatian to reach the second round of the Australian Open. The world No 1 also admitted he has been under the weather for the past “four, five days” as he tries to win his 11th title here.

“He deserved every applause, every credit that he got tonight,” Djokovic said. “He’s an amazing player, I must say, so mature for his age. This is his moment, honestly. It could have easily been his match as well. He was a break up in the third. He fought, even though he was 4-0 down.

“He showed great mentality, resilience. He made me really run for my money, that’s for sure. Honestly, I have many, many praises for him. Many compliments.”

Despite a quick start by Djokovic on Sunday night, he quickly found himself in a slugfest against a player half his age. After narrowly edging out the second set tiebreak, Prizmic led by a break at 3-2 in the third set. The Croat played without fear against the best player in the world and the most famous person from their region, maintaining pressure on the Serb until the end. His performance earned him an ovation from Djokovic after the match.

“I certainly wanna be in his corner so hopefully he will invite me because he is gonna make some big things in his career, that’s for sure,” Djokovic said, smiling.

Djokovic was watched on Sunday night by his former coach Andre Agassi, a four-time champion in Australia and another player whose career endured deep into his 30s. “I started off very well for a 36-year-old,” Djokovic said. “Jeez, when you think about it, I’m double his age. Reality hits hard tonight. But I’m really trying to enjoy every moment on the court.”

Although his wrist issues appeared to be clear, a congested Djokovic admitted that he had been unwell over the past few days in Melbourne: “I am a bit under the weather for the last, yeah, four, five days,” he said. “You can probably judge by my voice. Look, it is what it is. You just have to try to deal with it and get over it and accept the circumstances and try to make the most of it.”

Aryna Sabalenka, the second seed, began her own title defence with a statement, demolishing the German qualifier Ella Seidel 6-0, 6-1 in 53 minutes.