Novak Djokovic tunes out crowd to move past Holger Rune and US Open first round

• Djokovic prevails 6-1, 6-7 (5), 6-2, 6-1 against Danish teenager
• Now has a perfect 22 wins from 22 matches at majors this year
• 2019 winner Andreescu rallies to improve to 8-0 at US Open

Novak Djokovic's bid for a record-setting 21st major singles title and the first calendar-year grand slam in men's tennis in more than a half-century got off to a winning but strangely muted start on Tuesday night with a four-set victory over the Danish teenager Holger Rune.

On court for the first time since missing out the Olympic podium with back-to-back losses in Tokyo nearly a month ago, the best player in the world and top seed in the men's draw battled through a patch of wobbly form, an opponent brimming with confidence and a less than accommodating Arthur Ashe Stadium crowd to win 6-1, 6-7 (5), 6-2, 6-1 in 2hr 15min and move within six victories of the rarest achievement in his sport.