After two weeks of high octane tennis, the US Open has produced two new champions in men’s and women’s singles. Novak Djokovic has claimed a record 24th Grand Slam. And Coco Gauff has finally fulfilled her promise with a victory over the new world number 1, Aryna Sabalenka. Some of the match-ups were intriguing, and so were their outcomes – Medvedev versus Alcaraz, for instance, and also Karolina Muchova versus Coco Gauff. The tournament has also produced two new world number 1s – Novak Djokovic and Aryna Sabalenka. But how long are they likely to hold on to their perch?