Novak Djokovic faced Casper Ruud on his first day back from injury when the former US Open finalist lost his first match on his ATP World Tour Finals debut as a fully fit player.
Djokovic, who won Wimbledon in July after recovering from an elbow injury, had only one win against Ruud in his previous six meetings but managed to recover from a second-set setback to secure a 7-6, 6-7, 6-4 victory in nearly three hours.
He needed to dig deep to finally see off his 190th-ranked opponent, who had his chances to win the match, and recovered from trailing 4-2 in the second set tiebreak, firing a forehand past Ruud’s head to break to take the set.
The 28-year-old world No3 made a poor start to the third set, failing to convert two break points, and a careless double fault from 40-0 up at 3-3 gave his opponent a break to trail 5-4. That prompted a fabulous match from Djokovic, who produced a tremendous display to clinch the match after two hours and seven minutes.
“I’m looking forward to a great year and being able to finish it on the court with an aggressive match like today,” he said. “It was hard, especially early on. I had to fight a lot to claw back in the second set after losing my serve. I had three chances to break back, but he played some very good stuff on those points.
“I fought a lot and managed to get through it, and I’m just grateful to be in the next round of the tournament. I was nervous in the end. It was a difficult match for me and I had to keep fighting because he was playing well. I gave everything in every moment, and it’s a win that I won’t forget.”
• This article was amended on 7 August 2017 to change the date of the US Open final.