Chung crowned Next Gen ATP Finals champion

South Korean Chung Hyeon has doused the fire of Russian Andrey Rublev to win the inaugural Next Gen ATP Finals in Milan.

Chung was outplayed in the first set and was behind in the second before taking control to win 3-4 (5-7) 4-3 (7-2) 4-2 4-2 to go through the five-day round-robin tournament unbeaten.

The 21-year-old champion pocketed a $390,000 ($A510,000) cheque in the process.

A high-quality final full of sublime ball-striking was a fitting end to a promising debut for an event which has experimented with a range of innovations such as shorts sets, ‘sudden-death’ deuces and on-court coaching.

The 20-year-old Rublev, at 37th the highest-ranked qualifier for the event restricted to players aged 21 and under, lost his cool as the relentless Chung turned the match around.

But the Muscovite showed tremendous resolve to survive a deciding point deuce, effectively match point, when serving at 1-3 in the fourth set, winning a ferocious baseline exchange.

The 54th-ranked Chung showed his first sign of nerves when he double-faulted at 30-30 in the next game but Rublev wasted the break point with a shanked forehand.

At deuce Rublev still had the chance to drag the set into a tiebreak but Chung struck a forehand winner to seal victory in just under two hours of compelling action.