Acapulco (Mexico): Serbian world No. 2 Novak Djokovic held off a stiff challenge from big-hitting Argentine tennis star Juan Martin del Potro in the second round of the Abierto Mexicano Telcel to rally from an early deficit and finish off his 4-6, 6-4, 6-4 victory on Thursday.

Djokovic and Del Potro frequently bring out the best in each other and that was the case again at this hard court event, where the fans were treated to a contest featuring gruelling baseline rallies and punishing forehand winners, reports Efe.

The Serbian's superior consistency gave him a slight edge down the stretch, although he had to rally from a break down in the third set to pull off the narrow victory.

Djokovic, who fell to Del Potro in the first round of the 2016 Rio Olympics men's singles, lost his serve in the seventh game of the third set but responded emphatically to claim the final three games of the match.

"Every match that I've played against Delpo in the past couple of years has been very close, really enjoyable to play and great for the crowd to watch," the top-seeded Serbian said after the game.

"I cannot believe that the stadium was full at 1 a.m., so I want to thank all the people who came to watch us and support tennis."

Next up for Djokovic in Thursday night's last quarter-final match-up will be talented young Australian Nick Kyrgios, who advanced to the final eight with a 6-2, 6-4 victory over American Donald Young.

In other second-round action on Wednesday night, Spanish No. 2 seed Rafael Nadal cruised into the quarter-finals with a 6-1, 6-1 shellacking of Italy's Paolo Lorenzi.

Afterward, Nadal was asked why he had his right knee taped in his first two matches.

"I felt something in training (prior to his match Tuesday against Germany's Mischa Zverev)," the Spaniard said, adding that he felt much better on Wednesday.

Looking ahead to his next opponent, diminutive Japanese 21-year-old Yoshihito Nishioka, Nadal said the qualifier would come into the contest with confidence having already won four matches in Acapulco.

Austrian No. 4 seed Dominic Thiem and American Sam Querrey will square off in the other quarter-final on the top half of the draw, with the winner to take on either Djokovic or Kyrgios.

The winner between Nadal and Nishioka will play either American Steve Johnson or third-seeded Croatian Marin Cilic.