Atletico Madrid is a tough opponent for any big club in Champions League but by understanding Real Madrid very well, they are one of most unwanted opponents with Real Madrid. Similarly Bayern Munich did not want to play with Bayer Leverkusen in Champions League too but destiny attracts them playing against each other.
I think both pairs are hardly predictable as Bayer Leverkusen and Atletico Madrid even can be considered as weaker but not too considerable, and they are able to play outstanding matches to beat stronger opponents like Real Madrid and Bayern Munich. Personally, Atletico Madrid have better chance to win than Bayer Leverkusen.
Both teams have another opportunity to one up the other when they meet tomorrow and another thing about Atletico Madrid is that their mentality have changed ever since they played Bayer Leverkusen, win has always been in their eyes and I see them as a more stronger side than Madrid like these guys can defend and at the same time play a very fast counter attack and Madrid looks like the soft side in this game.
It really going to be a very tough game for both sides, usually when both teams meet in the Domestic League side, La Liga and, or Champions League competition, It has always been a tough game, and here again they're meeting tomorrow, one thing that has differentiate them and made Real Madrid standout most of the time, is that Madrid usually play all their champions league games with great experience, especially when it gets to the knockout stages of the competition. Therefore, I'm expecting Real Madrid to become Victors of the match base on having more experience than ATM.