The kingdom is putting on the richest tennis exhibition in history, but its wider ambitions in the sport have contracted.

RIYADH, Saudi Arabia (AP) — Rafael Nadal starts his pre-retirement farewell tour against Carlos Alcaraz on Thursday at the Six Kings Slam, and Novak Djokovic faces Jannik Sinner at an exhibition event that awards money but no ATP ranking points and is Saudi Arabia's latest foray into tennis.

The quarter-final were held on Wednesday 16 October, with Sinner beating Medvedev to set up an encounter with Djokovic a day later, and Alcaraz likewise booking his spot in a semi-final against Nadal. After the semi-finals, competitors will then have a rest day, before a final and a third-place play-off on Saturday 19 October.

Carlos Alcaraz, winner of four majors, crushed the Dane Holger Rune (6-4 and 6-2) in his first game and now will face Nadal in the semi-finals of the tournament with this set to be the last ever game between the two idols of Spanish tennis, with the Davis Cup in Malaga next month set to mark Nadal’s definitive farewell from the sport.

Six Kings Slam viewers voiced their frustration over the tournament's camera angle just minutes into Daniil Medvedev's clash with Jannik Sinner. We'll be bringing you the very latest updates, pictures and video on this breaking news story.

Novak Djokovic and Jannik Sinner will battle in a blockbuster semi-final at the Six Kings Slam in Riyadh. The Serb returns to Saudi Arabia a year after fighting against Carlos Alcaraz, hoping for another memorable duel against the world's best player.

The Six Kings Slam is the most lucrative exhibition tennis tournament ever, taking place in Riyadh, Saudi Arabia, as part of the country’s annual sporting season.

The exhibition tournament held in Riyadh, where the winner takes home six million (more than double the US Open), will be the penultimate for the Balearic player before his retirement in the Davis Cup Rafa Nadal,