Novak Djokovic plays tennis with fan after 'marriage proposal' - video
The Serbian tennis star was on the practice court during the Arthur Ashe Kids' Day on Saturday (August 25) when a young fan shouted out: "Will you marry me?"
After the crowd met his marriage proposal with laughter, Djokovic invited him onto court for a quick serving practice.
Carly Rae Jepsen and The Wanted were among celebrities who appeared during the annual Kids' Day on Saturday.
Djokovic will begin his defence of the US Open title at Flushing Meadows later today (August 28).