#1 Barcelona vs Bayern Munich (UCL SF, 2013):

If you think a 4-0 defeat against Athletic Bilbao in a pre-season competition was embarrassing, what will you call a 7-0 thrashing in the semi-finals of the Champions League?
Clueless? Just like Barcelona side against Bayern Munich in the semi-finals of the 2012-13 Champions League?
The Catalan side was on fire in La Liga and ended the season with 100 points. But it was the European competition where they suffered in pain.
Both semifinal matchups this season pitted a German giant against a Spanish counterpart. Fans were hoping to see Barcelona vs Real Madrid in the final of the Champions League. But Bayern and Dortmund had other plans.
Especially Bayern Munich, who handed Barcelona their worst defeat in the last 15 years. The Bavarians beat Barcelona 4-0 at Allianz Arena. Barcelona's main man, Lionel Messi was unavailable for the fixture due to injury, And the Argentine was sorely missed by the Catalans during the miserable 180 minutes.
Thomas Muller scored a brace as the Catalan defence looked helpless on the night, killing the tie in the first leg itself.
But, the Germans did not stop just there and scored another 3 goals at the Camp Nou. The Bavarians entered the final of the Champions League in style by mercilessly thrashing Barcelona 7-0.