The youngster dressed in a dark hoodie and cap, avoided security to run up to his hero and ask for a selfie in the 87th minute of the clash with Latvia.
Ronaldo obliged to hand the fan a memento snap before he was led off by security.
The Real Madrid mega star was spotted giggling with wing pal Ricardo Quaresma after the incident which stopped play at a goal kick for a few moments.
Ronaldo helped his side thrash Latvia 3-0 to move within three points of top placed Switzerland in World Cup qualifying.
It took until the closing stages of the first half before Ronaldo opened the scoring – but he played a starring role from that point on.
The Real Madrid winger had felt aggrieved with the way that he was targeted by the Latvian defence in the early stages of the match and called on the referee to take action.
But he soon got back to doing what he does best as he stooped low to head home at the back post in the 41st minute, as his run went unnoticed by the defence.
It was the same scenario in the second half as Ronaldo found himself unmarked inside the six yard box and was able to head the ball into an empty net.
He had the chance for a hat-trick just minutes later – but passed up the opportunity to finish.
Ronaldo picked up the ball on the edge of the penalty area but instead of turning and shooting, he picked out the marauding run forward of Andre Silva, who drilled across the face of the goalkeeper.
There was one final chance for Ronaldo to get his third, but his effort could only hit the side netting with 10 minutes remaining.