And once Federer was out of contention in the same tournament and Nadal had formally withdrawn from the World Tour Finals, Djokovic was assured of the year-end No1 for a fifth time.
The Serb is one of only four players in rankings history (since 1973) to have clinched the year-end top spot on five or more occasions, joining Pete Sampras (six), Jimmy Connors (five) and Roger Federer (five).
But no-one else has reclaimed the No1 ranking from outside the top 20—and Djokovic was 22 in June—in the space of a single season, and he also became the oldest man to finish as year-end No1.
It was a remarkable renaissance after a long absence with elbow problems, and after an early exit at the Australian Open, he underwent surgery.
By the time he hit the clay of Rome, he had turned a corner, and when it came to the grass season, everything began to fall into place: finals at Queen’s, title at Wimbledon, the title at the Cincinnati Masters—ticking off another first, the complete set of nine Masters titles—and then the US Open and Shanghai Masters.
That set a 31-2 run through six months, and he comes to London, where he has qualified 11 times, as the favourite to equal another of Federer’s records, a sixth World Tour Finals trophy.
It was at the O2, before he opens his campaign Monday, that he was presented with one of the biggest trophies in tennis, and he was justifiably proud. The gold “1” emblazoned on his white jacket spoke volumes.
“Next to the Grand Slams and the ATP Finals, being No1 is probably the ultimate challenge in our sport. It’s the pinnacle of the entire season. I’m very proud of that achievement and it’s extra special this year because of the whole process and the journey that I’ve been through in the past 15 months, in particular, the past 8-10 months.
“After February’s elbow surgery, it looked quite improbable that I’d be in this position as a year-end No1. Not just because of the rankings, being No22, but also because of how I felt on the court and how I played.
“But there was always a part of me that believed I could make it back and I never thought it was impossible.”
The trophy was presented by the President of the ATP, Chris Kermode, to the current President of the Players Council, in front of a still full Centre Court at the O2.
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BIOGRAPHY: Ethan Hazard
BIOGRAPHY: Daniel Sturridge