Six Kings Slam QF previews and predictions: Zverev vs. Fritz, Sinner vs. Tsitsipas

Defending champion Jannik Sinner has to play a quarterfinal match at the Six Kings Slam, which will come against Stefanos Tsitsipas on Wednesday. Alexander Zverev and Taylor Fritz are also taking the court.

Alexander Zverev vs. Taylor Fritz

There are no easy draws in an event that features six players in the top 24 of the rankings, but this is an especially bad one for Zverev. The 28-year-old German hast los an almost hard-to-believe six consecutive matches to Fritz, whom he will meet again in the quarterfinal of the Six Kings Slam on Wednesday in Riyadh, Saudi Arabia. Fritz’s current hot streak in the head-to-head series began at Wimbledon in 2024 and most recently continued with a 6-3, 7-6(4) victory at the Laver Cup. The 27-year-old American has was won nine of their 14 encounters overall.

It’s hard to see Zverev suddenly turning things around in Riyadh. Sure, this is an exhibition–but Fritz has generally played well outside of the main tour such as in the Davis Cup, Laver Cup, and United Cup. Perhaps no one in the sport plays more than the world No. 4. He simply loves playing, regardless of the setting or situation. And he especially loves playing against Zverev, who is 3-5 in his last eight matches dating back to the U.S. Open.

Pick: Fritz in 2

Jannik Sinner vs. Stefanos Tsitsipas

Sinner lifted the trophy in 2024 and–with a $4.5 million bonus going to the champion–he will undoubtedly be motivated to defend the title. The second-ranked Italian will also be eager to get back on the winning track after retiring from the Shanghai Masters during a third-round match against Tallon Griekspoor.

Up first for Sinner on Wednesday is a matchup with Tsitsipas, who surprisingly leads the head-to-head series 6-3. However, the 24-year-old has won two of their last three meetings and each of their last two on hard courts (albeit indoors). Tsitsipas has not played well in 2025 and he is a horrendous 3-7 in his last 10 matches, so there is no reason to anticipate an upset.

Pick: Sinner in 2