Zverev held serve to start the fourth set but all eyes are on Alcaraz. Credit: Getty ImagesHe does have the two-set lead but is a shadow of himself now, this is tough viewing. Alcaraz summoned a 200km per hour serve during the last game and it had no legs in that serve. He held serve despite his ailments. Alcaraz leads 6-4, 7-6, 6-7, 1-1 with Zverev to serve next.