World No.1 Novak Djokovic played only one of two scheduled sets in his opening match of the season on Friday as he grappled with a nasty blister on his racket hand ahead of the Australian Open.

The 17-time Grand Slam winner didn't appear for the first set against young Italian Jannik Sinner at an exhibition in Adelaide, just hours after emerging from two weeks' quarantine, with fellow Serb Filip Krajinovic taking his place.

But with a nearly full crowd at Memorial Drive, Djokovic said he couldn't stay away and came on court for the second set, to huge roars.

"I'm sorry that I didn't step on the court from the beginning. I had to do some treatment with my physio and I wasn't feeling my best the last couple of days," the defending Australian Open champion said after winning his set 6-3.

"I didn't know how I was going to react, but I wanted to play, I wanted to get out here."

"Thank you so much for making our day and making our year. We didn't play in front of this big a crowd in 12 months, so this is something very special," he added.

Television pictures showed a raw blister on the palm of his right hand where he grips the racket. Djokovic said it was painful, although it didn't appear to hamper his shot-making.

"It's not easy, but it's part of what we do. We're professional athletes, we learn over the years to play with the pain. It's just a question of whether the pain is bearable or not," he said.

"So obviously, coming off a hard training block and having the ATP Cup and Australian Open around the corner, you don't want to risk it too much.

"But the emotion was so strong in me to come out on the court today, seeing almost full stands, I just had to play. That's it, I had to play."

Later in the evening, World No. 2 Rafael Nadal beat U.S. Open champion Dominic Thiem 7-5, 6-4. In the women's singles, Serena Williams beat Naomi Osaka 6-2, 2-6, 10-7, while second-ranked Simona Halep beat No. 1 Ashleigh Barty 3-6, 6-1, 10-8 in the final match of the night. 

(With inputs from AFP, AP)