TURIN - Jannik Sinner edged towards becoming the first ever Italian to reach the last four of the ATP Finals on Tuesday after a thrilling 7-5, 6-7 (5/7), 7-6 (7/2) win over Novak Djokovic.
World number four Sinner needed a straight-sets victory in front of enthusiastic home support in Turin over tennis icon Djokovic to guarantee passage from the Green Group with a match to spare.
And while the 22-year-old couldn't quite make that happen, a superb performance gave him his first win in four attempts over Djokovic, who is bidding to win for a record seventh time at the year-ending tournament.
"It means a lot to me," said Sinner on court.
"When you win against the world number one who has won 24 Grand Slams it's obviously in the top-top."
Fans made an almighty din for Sinner, chanting his name to the rafters once he claimed victory in an exciting, three-hour contest which ran way past midnight at the Pala Alpitour.
Sinner has had the best year of his career and looks be fulfilling the promise he has long shown, winning four titles this season including the Toronto Masters, and looks on form in Italy.
He made the first breakthrough when he capitalised on Djokovic handing him advantage in game 11 with a double fault, moving 6-5 ahead with a big backhand before claiming the set with a service game to love.
Djokovic pulled level after a bruising second set in which neither player faced a single break point, but after fighting back from 4-2 down in the decider he wilted in the tie-break and ended his winning run at 20 matches.
Both players' fate will be decided in the final round of group matches, with Djokovic facing Hubert Hurkacz who has stepped in for Stefanos Tsitsipas after the Greek pulled out of the tournament with a back injury against Sinner's next opponent Holger Rune.
And Rune will have the benefit of having played just three games before being awared a straight-set win.