Alcaraz is 16 years Djokovic's junior but could face a tough test in his pursuit of a sixth Grand Slam title having lost five of his eight matches against the Serb
Swiatek and Ruud will face the top-seeded team of American Jessica Pegula and Briton Jack Draper in the semi-finals
The Australian, a five-time Olympic gold medalist, is red-hot favorite in the 200m freestyle event in Singapore
American great Katie Ledecky put the disappointment of missing out on the 400 freestyle title on Sunday behind her with a strong swim in her signature event -- the lung-bursting 1,500 freestyle
