Novak Djokovic's winning streak was halted at 19 matches as home favorite Jannik Sinner roared to a tight, three-set victory in front of a partisan ATP Finals crowd on Tuesday.

The earlier Green Group clash was a non-event as Stefanos Tsitsipas retired injured against Holger Rune, but the evening ticket holders were treated to a match of jaw-dropping quality.

After more than three hours of an absorbing toe-to-toe battle in which neither player took a backward step it was world No. 4 Sinner who seized his chance in the deciding set tiebreak to finally crack Djokovic's resistance.