Two red cards.

Those were the major turning points of the two Champions League matches on Wednesday. But they changed the games in different ways.

The first of the red cards came just three minutes into the game between Shakhtar Donetsk and Bayern Munich. Entering the match, the two sides were tied 0-0 and Shakhtar might have held some hope of an upset. After all, this was a Bayern side without Xabi Alonso (who was also sent off in the previous leg) and one that had struggled to win the second leg in the last two Champions League matches.

But the moment Oleksandr Kucher took down Mario Goetze in the third minute of play, the game's fate was sealed.

Thomas Mueller scored on the ensuing penalty and it was pretty much over after that.

With 11 men facing them, Bayern had to battle for space to make its possession game click. With one extra man on the pitch and the score in its favor from the get-go, there is basically no way that this game was not a clear victory.

Down 1-0, Shakhtar had no choice but to attack and go for an equalizer. But that left the side exposed at the back and, by half time, Bayern held a solid 2-0. However, two-goal comebacks are not rare in this sport and Shakhtar knew that, if it wanted to advance, it had to go for the goals and pray that Bayern did not catch them exposed at the back.

It was a prayer that went unnoticed as the Bavarian side pounced on the Ukrainian team and scored five goals in the final 45 minutes. Shakhtar was demoralized after the 3-0 and 4-0 goals and simply fell asleep as Bayern amassed a whopping 7-0 victory, a massive change from the 0-0 game that was played out in the opening leg.

That was one red card, but here was the other.

Just 30 minutes into the game between Paris Saint-Germain and Chelsea, superstar Zlatan Ibrahimovic was sent off for a tackle on Oscar that, upon second viewing, was not deserving of such treatment.

So game-set-match, right? After all, Chelsea had the away goal in Paris and could simply sit back and shut down any PSG attacks. The team still attacked, but left itself open for resolute PSG counters that never bore fruit. And this was the key: despite being down, PSG, unlike Shakhtar, refused to be knocked out.

Chelsea would eventually take the lead, but instead of going for the kill, Jose Mourinho let his men hang back and absorb PSG's pressure. The end result? A David Luiz header that forced the game into extra time.

Mourinho then went back on the attack, earned a penalty kick and eventually a goal from Hazard. But PSG remained confident and Mourinho asked him men to sit back and defend yet again.

The result of that tactic? A header goal off a corner from Thiago Silva, almost identical to the one scored by David Luiz.

And once that had happened the game was over and Chelsea, which should have done what Bayern did, collapsed and saw its Champions League dreams come to an end.

In one match, a red card destroyed the hopes of one side in the face of a titan. In the other, it sparked a team to greatness and success.