Novak Djokovic was confirmed as year-end number one for a record-extending eighth time, but not before losing his cool.
Djokovic beat Holger Rune in his first match at the ATP Tour Finals in Turin on Sunday and it was a bruising encounter.
The pair spent more than three hours on court, and finished well after midnight, before the 36-year-old claimed a 7-6 (4) 6-7 (1) 6-3 win.
Frustrations did boil over for Djokovic, however, at the start of the third set.
He broke straight away to start the deciding set, only for this time Rune to recover the deficit immediately, prompting a frustrated Djokovic to stamp on two rackets, snapping the frames.
But he broke again to lead 4-2 and this time there was no way back for Rune.
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Djokovic told Prime Video: “It took everything. I saw in the first game when he fired shots from the baseline, I knew it was going to be a tough night for me. I thought he played great. I played great in some moments.
“Overall a win is a win. It was a very emotional win and a tough win knowing the significance of tonight’s match. After a really terrible second-set tie-break I think I played a really solid third set.”
The win was all he needed to confirm a record-extending eighth year-end number one.
It was a brilliant start for Djokovic as he also chases a record seventh ATP Tour Finals victory.
The fans were loving the Serbian superstar in Turin too, with one even cheekily asking him to sign his chest after that win over Rune.