Novak Djokovic branded the time violation he received during his ATP World Tour Finals match with David Goffin as "completely ridiculous".
The Serbian recorded his third successive win at the end of season tournament in London with a comprehensive 6-1 6-2 victory over Goffin, who replaced the injured Gael Monfils for the Group Ivan Lendl match.
His victory was not as straightforward as it sounds, though, as he was left berating the umpire and tournament supervisor in the fourth game of the opening set.
Djokovic was penalised by umpire Fergus Murphy while preparing to serve following a lengthy point decided by a superb Goffin lob, a decision that continued to anger the former world number one even after his triumph.
"You heard my opinion on the court, I don't need to repeat it again," he told Sky Sports.
"To me it's really not fair that in the fourth game of the match I get a code violation for going a few seconds over the time and I spoke to [the tournament supervisor].
"He didn't do anything and I thought he should have to be honest. I understand that there is a rule, but also there is some understanding of the game.
"It was a long point, a long exchange in the match, it is the first time that I went over the allowed time between the points and he gives me a warning.
"He doesn't recognise the situation and the circumstances we were in, because if he did he would just tell me, 'okay, you've got to hurry up a bit', because with most of the guys it's like that.
"I don't understand why he did it, but I guess we've got to move on."
An irate Djokovic added: "I know I'm one of the players who takes more time between points on the Tour with my ball bouncing and everything and I accept that fact, but what I'm saying is that at least there should be a fairness to this rule by saying if you go over the limit for the first time, you have plenty of time [to say]: 'Hey, Novak, just speed up a little bit.'
"If you give me the warning after that, I won't say a word, but don't give me the first time I went over in the beginning of the match - it's completely ridiculous."