set Real Madrid on their way to the semi finals with an extra time goal - which should have been ruled out for offside.
Ronaldo notched his 99th Champions League goal and his second of the evening after picking up a floated Sergio Ramos pass and shooting right footed past Bayern Munich goalkeeper Manuel Neuer.
Real went on to win 4-2 on the night and 5-3 on aggregate, Ronaldo scoring a hat-trick and his 100th Champions League strike - but his second should not have counted.
Replays showed Ronaldo standing a yard offside as the ball came over from Ramos, with Bayern's defenders raising their arms, expecting a flag that never came.
The offside drew a furious response on social media, including from a player for Real's biggest rivals, Barcelona.
Gerard Pique showed his disdain for the refereeing by simply tweeting '...' - a near silent response which got a big reaction and was re-tweeted over 65,000 times.
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This is what Ronaldo tweeted;
Another night to remember. Amazing win!! Great team work!