Djokovic launches Grand Slam quest with low-key win at US Open tennis

World number one Novak Djokovic won without playing his best to reach the second round of the US Open on Tuesday in his quest for a calendar-year Grand Slam and a record 21st major title.

The 34-year-old Serbian star dominated much of the way in beating 18-year-old Danish qualifier Holger Rune 6-1, 6-7 (5/7), 6-2, 6-1 after two hours and 15 minutes in the night feature at Arthur Ashe Stadium.

"It wasn't the