A persistent wrist injury forced Nadal to curtail his 2016 season prematurely after the Shanghai Masters in October, but his competitive return ended with a largely comfortable victory on Tuesday.

The Spaniard, who claimed his fourth Mubadala World Tennis Championship in Abu Dhabi last weekend, suffered an early blow when he was broken by Dolgopolov in game three, but stepped up a gear and won five straight games to take the first set.

A frustrated Dolgopolov confronted the umpire, who forced a point to be replayed when a ball fell out of the pocket in his shorts, and he failed to convert either of the two break points that came his way in the second set as Nadal advanced.

Next up for the Spaniard is Mischa Zverev, who defeated Australian qualifier Alex De Minaur 6-3 6-3.

Diego Schwartzman overcame Sam Querrey 6-2 6-4 to set up a second-round meeting with defending champion and top seed Milos Raonic.

Yoshihito Nishioka failed to serve out the second set and force a decider in a 6-4 7-5 loss to Viktor Troicki, who faces Stan Wawrinka next.

Sixth seed Lucas Pouille needed two tiebreaks to see off fellow Frenchman Gilles Simon 7-6 (8-6) 7-6 (7-4).

Qualifier Jared Donaldson earned a second-round match against Kei Nishikori by beating Gilles Muller in straight sets, while wildcard Sam Groth edged out Pierre-Hugues Herbert.