Hey dude. This is how I see it:
First half was legit one of the worst of the season, largely due to playing Busi and Masch in midfield. Neither really knew their role, and subsequently, that messed up our defense, especially down the left (Adriano

) We were really, really lucky to get to half time at one nil.
Half time, we brought Rak on for Adriano, a great move from Lucho. Second half was one of the best halfs we've had all season. Possession-ed them off the park, Rak proving a massive difference. Our back line were really outstanding, Masch was reading the game so much better, Mathieu was moving into positions for Neymar (who was excellent defensively) to pick up the ball and soak up pressure. We didn't create a whole pile -- Messi looked exhausted -- but in a very Simeone way, we were impossible to beat. I would say we gave up one half-chance in the second-half. Also, brought on Sergi Roberto for a tiring Xavi and he was very astute, filling the gaps, ticking over, another good move.
Summation - First half = bad, second half = brilliant - team looked very tired, lots of good moves by Lucho, and great organization and mental strength. I'm impressed.