4) Marin Cilic shocked by Jack Sock
Coming into the tournament, Marin Cilic was a heavy favourite to challenge the likes of Murray and Djokovic for the title. He had already won the event in 2014. Not only that, he was in supreme form in the run-up to the US Open and had even ended Andy Murray’s 22-match unbeaten streak in the final of the Cincinnati Masters 1000 event.
Naturally, the big-serving Croat, seeded seventh, was the favourite to put USA’s Jack Sock to bed in the third round of the US Open. But 26th seed Sock was having none of it.
He produced a flawless display of tennis to the surprise of the Croat who surrendered meekly. Sock cruised to a clinical 6-4, 6-3, 6-3 victory in a match that was even less competitive than the score would indicate. So much for being a favourite.