The soccer world was stunned on Tuesday when Real Madrid dismantled reigning European Champions Bayern Munich in the second leg of the Champions League semifinals.

Los Blancos entered the game with a 1-0 edge on Munich and many expected the second leg to be extremely competitive. But within 20 minutes it was 2-0 and before the first half it was 3-0.

Here are a few reasons why the Bayern Empire crumbled over the course of 45 minutes. 

1. Is Manuel Neuer the best keeper in the world?

For many years, Real Madrid's Iker Casillas was considered the top keeper in the world. After relatively little action in 2013-14, Casillas has been knocked off his pedestal. In his place is Bayern keeper Manuel Neuer, who most recognize as the best in world (alongside Thibaut Courtois). But unfortunately Neuer was not at his best on Tuesday. The netminder nearly cost his team early on when he made an aggressive play for the ball outside the area. It wound up on the foot of Gareth Bale, who fired it over the net. A few minutes later he fired it out of bounds from a goal kick. On the opening goal, he stood in his goal instead of challenging the ball. It was not his fault, but he seemed a bit tentative on the play. After the second goal, he left a rebound in the box that nearly cost his team a third goal; fortunately he recovered in time to grab the loose ball.

The third goal that he gave up against Cristiano Ronaldo was one that he could have; it was not completely his fault but he managed to get a hand on it and could have stopped the shot.

Meanwhile, Casillas was not tested at all in the first half.

2. No answers for aerial play

A year ago, Bayern Munich took down Barcelona by taking advantage of the aerial play. A few of the seven goals against Barcelona were the result of aerial play. A year later, Munich has not been able to develop that advantage and it cost the team on Tuesday. Madrid cashed in on two set pieces for the opening two goals; both goals came off the head of Sergio Ramos. Munich looked like Barcelona of last year.

Even on their own corner kicks, the team seemed to lack box presence and the Madrid defense was able to do away with the aerial threat.

On the flipside, Madrid's defense was privy to every single aerial attack launched by Munich; Pepe dominated the air in Madrid's box through both matches, as did Ramos. It is rather shocking to see a team that was so dominant in the air a year ago look so lost.

3. No Answer on the right flank

In the first leg, Pep Guardiola put Rafinha on the right side to take down Cristiano Ronaldo and Fabio Coentrao. After that experiment failed, the manager put Philipp Lahm on the right to take care of that problem. However, it continued to be an issue throughout the second leg as Madrid constantly exploited that wing. Interestingly enough, Ronaldo was not always on that flank, but constantly moved over to the right side and let Angel di Maria take over that side of the field. It seemed to confuse the Bayern defense and left the team susceptible to the counter attack.

4. Absent Ribery

Franck Ribery was terrific over the weekend and many expected him to step up his game and give Munich strength on the wings. Arjen Robben was solid throughout, but the Frenchman was far from the superstar that he was in 2012-13 when he became Europe's top player and was a Ballon d'Or contender. He was frustrated throughout the first half by Dani Carvajal and at one point slapped the Spaniard in the face (as replays showed). He failed to make any impact throughout the game and will be one of the big goats for the team's UCL failure. He was mercifully replaced in the second half after a disastrous performance for his club. Maybe he did not deserve the Ballon d'Or after all.

5. Power outage

Bayern Munich's offense was dynamic a year ago and under Guardiola, the Bavarians had seemingly found a new gear in the opponent's half. However, over two legs, the team looked lost against Madrid's surprisingly solid defense. The team had one good scoring chance in the first leg and did not manage a single dangerous shot in the first half of the second leg at home. Despite having 69 percent of the possession, Munich did not have a single shot on target in the entire first half; Madrid had three and scored on every single one of them.

The second half was a bit better in the early going as Munich's possession game was played with a quicker pace. But at the end of the day, the team simply did not have the creativity to unlock a solid Madrid defense. It was possession for the sake of possession. The offense lacked a player to pass to in the middle and relied heavily on its flank play to save the day. Ribery was absent and Robben was overwhelmed. The additions of Mario Goetze and Claudio Pizarro were huge mistakes. It will be interesting to see how Robert Lewandowski, who can create goals out of nothing, does next season.