- Lee Sin
For those that are not aware, M5 had a massive lead coming into mid and late game, and it very much looked like M5 was going to win this game. At one point, M5 had a lead of 10+ kills as well as 20K+ in gold. They even took Baron 3-4 times. But M5 decides to just simply camp around CLG EU's base and wait for the "perfect opportunity" to engage in the game-winning teamfight instead of just going for the mid inhib turret push and basically "opening the floodgates to victory"
M5's mistake was waiting way too long - even with the MASSIVE lead they had - and the game went to the point where one mistake on either side of the team could basically cost them the game. CLG EU's comeback started when M5 engaged in a teamfight at the bot inhib turret, but were not positioned correctly and it resulted in a 4-1 trade in favor of CLG EU. Unfortunately, they couldn't push to M5's base, but this teamfight was definitely the turning point in favor of CLG EU.
Later on, CLG EU began pushing out of their base and began to camp out in M5's jungle. Karthus (Alex Inch) got caught at their own blue and that allowed CLG to push down the bot inhib. CLG EU decided to attempt Baron sometime after that, but was thwarted. In that one final teamfight afterwards, Vladimir got caught and nuked, and everything started to go south for M5. CLG EU cleaned them up, and immediately went for the Nexus turrets and the M5's Nexus to cap off their AMAZING comeback in a 61 minute game.
tl;dr - If you didn't see it, M5's actions is one of the BIGGEST throws in a LoL tourney. Ever. #1 throw of all time by a pro team. This game is very likely to be the best comeback in the history of LoL. Also, this game proves that comebacks are definitely possible, and no one should give up until all options are exhausted.