Jannik Sinner beat Carlos Alcaraz 6-7 (5), 6-3, 6-3 for the championship in the Six Kings Slam exhibition Saturday after Novak Djokovic topped Rafael Nadal 6-2, 7-6 (5) in the third-place match. While Sinner and Alcaraz probably have plenty of future matchups in store, Djokovic and Nadal may have been playing for the final time in one of tennis’ great rivalries. Djokovic won the match between rivals who have combined for 46 Grand Slam singles titles.