Novak Djokovic has retired from his Australian Open semifinal against Alexander Zverev after losing the first set in a tiebreak. Djokovic missed a regulation putaway volley on top of the net down 5-6,

Alexander Zverev chided the crowd after they booed Novak Djokovic for retiring due to injury after the first set in an Australian Open semifinal.

And just as Djokovic had a couple of hurdles by the names of Roger Federer and Rafael Nadal to deal with, Sinner is not alone among the newest generation of tennis stars. His top rival at this point is Carlos Alcaraz, who has four Slam victories at age 21 — and won all three matches he played against Sinner in 2024.