Rafael Nadal said regaining the winning feeling has given him confidence, as he continued his flawless record at the Rio Open.

Inaugural and defending champion in the Brazilian capital, Nadal downed local hope Thomaz Bellucci 6-4 6-1 on Tuesday to open his clay-court season in positive fashion.

The world number three, who has endured a turbulent start to the 2015 season, said he was simply happy to be back competing.

Nadal played only three tournaments post-Wimbledon in 2014 due to a wrist injury, and his 2015 campaign started poorly with a first-up loss to Michael Berrer in Doha.

The Mallorcan said his one-hour-and-31-minute battle with Bellucci gave him confidence.

"All victories give you confidence and let you keep competitive, so the more you compete [it] is good because it means you are winning games and playing more hours on the court," Nadal said.

"So everything is helping you to recover your rhythm, confidence and the competitiveness. 

"About the game, I think I played well if you consider it was my first game on clay in a long time. 

"I played a serious game without doing anything complicated because I knew it wasn't the day to do that."

Nadal said his lack of regular tennis in the past eight months has grown his hunger to compete.

"Personally, if you ask me in Barcelona, after playing in Monte Carlo if I needed to win a game to take confidence, I answer 'no' but if you ask me that in Qatar after seven months out, I tell you 'yes', and it's the same here," the 14-time major winner said. 

"Winning games gives you more confidence to play confidently and recover your positive feelings."