Novak Djokovic survives scare to keep calendar slam bid on track at US Open

Novak Djokovic is into round two (Frank Franklin II/AP)

Novak Djokovic’s bid for tennis history at the US Open got off to a bumpy start against 18-year-old Danish qualifier Holger Rune.

The world number one, bidding for a fourth Flushing Meadows title and to become the first man to complete the calendar grand slam in 52 years, dropped the second set against the spirited Rune.