Novak Djokovic will finish the year as world No. 1 for a record-extending eighth time after beating Holger Rune 7-6 (7-4), 6-7 (1-7), 6-3 in his opening match at the ATP Finals on Sunday.

The 24-time Grand Slam champion needed one win, or for young rival Carlos Alcaraz to lose, in order to secure the top spot in the ATP rankings for 2023 and prevailed in a three-hour Green Group clash against Rune.

Djokovic, on a run of 19 straight wins, has had an age-defying year, winning three Grand Slams and now holds the men's record with 24 career titles.