Paris: Spain's Rafael Nadal made sure he would top the ATP rankings at the end of the season when he beat South Korea's Chung Hyeon 7-5, 6-3 in the second round of the Paris Masters on Wednesday.
Nadal, who has never won the tournament, was a break behind in the opening set before stepping up a gear to set up a third round meeting with Uruguay's Pablo Cuevas.
Hyeon got off to a solid start and broke Nadal's serve as he moved 2-1 up but the Spaniard then won four games in a row.
The South Korean levelled for 5-5 but paid for his efforts as Nadal sealed the set with two successive games.
The world No. 1 made the decisive break in the eighth game of the second set and bagged a straightforward win on his second match point when Hyeon sent a forehand long.
Earlier, Germany's Alexander Zverev was knocked out in the second round when he slumped to a 3-6, 6-2, 6-2 defeat against Dutch journeyman Robin Haase.
The fourth seed, who has already booked his ticket for the season-ending ATP World Tour finals in London, lost his way in the match after Haase levelled at one-set all.
The 20-year-old Zverev converted his only break point in the first set to take the lead while Haase wasted six break chances.
But Haase played a bit tighter in the second set and it was enough to unsettle Zverev, who never threatened again in an almost empty AccorHotels Arena.