Eight days before the Melbourne Grand Slam and in their first appearances this year, the Spanish world number one won 7-5, 7-6 (8/6) in front of an enthusiastic 12,000 crowd in Incheon.

Neither will play competitively until the Australian Open, where Italy's world number two Sinner is the defending two-time champion.

South Korean organisers have not said how much the two players earned, but reports in Italy suggest each could pocket more than $2 million for the match that lasted one hour and 47 minutes.

It was not always entirely serious, the smiling duo treating a packed house to some trick shots between their legs, drawing cheers, and reacting to calls from the crowd by making heart gestures.

"Jannik, we finished the season playing together. We started the season playing together," Alcaraz said on court afterwards.

"So hopefully this season is going to be such a good one like last year. You deserve the best."

Alcaraz and Sinner have taken a stranglehold on men's tennis over the past two years, splitting all four Grand Slam titles between them in 2024 and 2025.

"It was a close match so a little bit of tension also," said Sinner.

"We were just happy to be here for the first time, seeing something new. It made us feel at home and we felt it on the court."

Arch competitors on the court but good friends off it, Alcaraz has the upper hand in their rivalry and came into the exhibition boasting a 10-6 head-to-head record.

They will be the favourites when the Australian Open starts in Melbourne on January 18, when the serious work begins.

Alcaraz, who at 22 is two years younger than Sinner, has never gone beyond the quarter-finals at the first Grand Slam of the year and it is the only major he has failed to win.