Jannik Sinner paid tribute to his "special friendship" with Carlos Alcaraz, after beating his rival to retain the Six Kings Slam.

The Italian was the last man standing for the second year running at the lucrative exhibition event, where he prevailed 6-2 6-4.

Sinner was beaten by Alcaraz in this season's French and US Open finals, but set his stall out early by breaking Alcaraz in the opening game on the way to dominating the first set.

Another break in the seventh game of the second set proved decisive for the reigning champion, who subsequently completed a successful defence of his title.

"I wish I could play like this everywhere," Sinner said in his on-court interview. "This season, we played many, many times and I also lost many times to Carlos. It is a huge pleasure and honour to share the court with him.

"At the same time, you want to get better as a player, and you need rivalries in the sport. So, it's nice to have a great rivalry and, more importantly, a great friendship off the court. We have a very special friendship, and it's very nice."

What a week Loved playing here, incredible atmosphere, and always a pleasure to share the court with you, @carlosalcarazThank you all for the support#SixKingsSlam @RiyadhSeason pic.twitter.com/Opm04kswhC

— Jannik Sinner (@janniksin) October 18, 2025

Between them, Sinner and Alcaraz have won nine of the last 10 majors, while contesting each of the last three finals.

The Spaniard, who displaced the Italian as the world number one following his Flushing Meadows triumph, conceded his rival was "just too good" on Saturday.

"We have a special relationship off the court, which is great," Alcaraz concurred. 

"People think when two tennis players are competing for great things, giving their best on the court, they cannot have a great friendship off the court and I think we [have seen] it's possible.

"When Jannik is playing at this level it is always difficult. Today, he was just too good.

"I always say when he plays such great tennis, it gives me motivation to go to the practice court, give 100% and try to be better. Sometimes, he is annoying, but he gives me extra motivation."

Earlier in the day, Taylor Fritz beat Novak Djokovic in the third-place match, after the 24-time major winner retired injured at the conclusion of the opening set.