by Leigh Copson from

We are down to four in the race to be crowned European Champions, and there could not be a better foursome in the Champions League semi-finals than Barcelona, Real Madrid, Bayern Munich and Borussia Dortmund.

At one time or another three of these four sides have been a favourite with the bookmakers – and only in this line-up could Dortmund be considered a dark horse! So whatever way the draw went it was going to throw up some tremendous ties, and it did do by pairing Barcelona with Bayern Munich and Real Madrid with Borussia Dortmund.

All four are capable of booking a place at Wembley next month – but all four have also shown some flaws and that makes these semi-final ties even more intriguing!

Barcelona looked to be heading out of the competition when they crashed to a 2-0 defeat at AC Milan in the last-16. They saved themselves with a 4-0 thrashing of the Italian side in the second leg, but that was not their last scare in this competition. Barcelona twice blew the lead as they were forced to settle for a 2-2 draw at Paris St Germain, and they then needed super-sub Lionel Messi to help them rescue a 1-1 draw in the second leg that saw them through on away goals.

Opponents Bayern Munich were expected to march into the quarter-finals in style after they beat Arsenal 3-1 in the first leg at the Emirates Stadium, but instead they limped into the last eight on goal difference after a 2-0 loss on their home turf.

Real Madrid appeared to be cruising into the semi-finals when they romped to a 3-0 win in the first leg of their quarter-final tie with Galatasaray, but the Turkish side threatened to pull off a massive upset before Cristiano Ronaldo finally killed them off.

Borussia Dortmund are somewhat fortunate to find themselves in the final four after a dramatic second leg in their last-eight tie with Malaga. A goalless draw in Spain looked set to cost them as they trailed 2-1 with eight minutes to go on their home turf, but they staged an incredible late rally that saw Marco Reus and Felipe Santana fire them into the semi-finals.

So having seen all four sides wobble at some point, there are no guarantees when it comes to who will step out onto the field at Wembley. What is guaranteed though is plenty of drama and excitement!