Real Madrid captain Sergio Ramos understands the whistles directed at Cristiano Ronaldo, but believes fans should be more thoughtful.

Ronaldo was jeered before he struck a hat-trick to inspire Madrid to a 4-2 extra-time win over Bayern Munich to send them into the Champions League semi-finals.

The Portugal star netted twice in extra time as the hosts at the Santiago Bernabeu recorded a 6-3 win on aggregate.

Ramos said the demands of Madrid fans meant he could see why Ronaldo was jeered by supporters in the quarter-final second leg.

"I understand the public and Cris," he said.

"He is a player who always gives the maximum. He can have good or bad matches like everyone.

"But people should think about it a little more. The Bernabeu has pounced on all the big players because they always ask for a little more.

"It is difficult to succeed here."

Ronaldo became the first player in history to score 100 Champions League goals during his quarter-final heroics.