Real Madrid superstar Cristiano Ronaldo has hit back at his critics and is surprised he continually has to prove himself.

Ronaldo scored a brace to help Madrid to a 3-1 win over Borussia Dortmund in the Champions League on Tuesday.

The Portuguese star’s domestic return has not gone to plan, unable to net in two La Liga games since coming back from suspension.

But Ronaldo, 32, is growing tired of the constant criticism, saying he has already proven himself.

‘It seems that I have to keep showing exactly who I am in every match,’ he told Atresmedia after his 400th Madrid appearance.

‘I am surprised by what the public thinks of me, my numbers speak for themselves, I am an exemplary professional and I always have a clear mind.

‘The criticism is getting worse.’

Gareth Bale opened the scoring with a stunning volley for Madrid at Signal Iduna Park before Ronaldo’s second-half double.

Ronaldo said Zinedine Zidane’s men stepped up, as the La Liga giants won at Dortmund for the first time.

‘Before the game we spoke about how much we wanted to win in Dortmund,’ he said.

‘We did what the coach told us, the team has been phenomenal, creating opportunities and it isn’t easy to score three goals here.

‘We played well.’

-This story originally appeared on FourFourTwo.co.za