The Spaniard will also get another chance to do so later this month at the ATP World Tour Finals in London, although defeat today seems highly unlikely.
Nadal has played Chung just once before, beating him in Barcelona earlier this year.
The 21-year-old from South Korea is yet to win a title in his career and comes up against Nadal in search of his 76th.
The world No 55 lost to David Goffin last week in Basel 6-4, 6-1 but beat Misha Zverev 6-0, 6-2 in the first round in Paris.
Rafael Nadal vs Hyeon Chung LIVE from the Paris Masters
1.15pm: There it is. Pouille finishes off Lopez with minimal fuss, sealing a 6-3, 6-4 win for a place in the next round where he will either face Britain’s Kyle Edmund or American Jack Sock.
But back to today. It’s nearly Nadal O’Clock.
12.50pm: Afternoon! A bit of history looks set to be created today if Nadal does what everyone expects him to do and breezes through htis second-round encounter.
He wil become the first man in his 30s to end the year as world No 1, a testament to his ongoing longevity and truly remarkable talent.
Roger Federer had been pushing him close, another man with those two qualities in spades, but the Swiss pulled out of the Paris Masters to manage a back problem ahead of the ATP World Tour Finals.
Nadal and Chung will be on court in a few minutes here, just as soon as Lucas Pouille has dispensed with Feliciano Lopez – the Frenchman leads 6-3, 2-1 with a break in the second set.