I was there too, up in the gods. What I can remember most is the roar that shook the O2 like a wave hurtling towards the stage just as Christine started the second verse. An amazing moment.
This "guerilla" cut captures it all rather well (although I suspect some of the shots might be from her second appearance).
https://www.youtube.com/watch?v=0fe23suPuEY
Oh dear. I'm blubbing all over again.