I completely blanked during a big client pitch meeting

I was in a conference room with three people from a potential new company, and about five minutes into my talk, my mind just went totally empty. I forgot the next part of my plan. I took a deep breath, said 'Let me just check my notes for a second,' and looked at my pad to find my place. It felt like forever but was maybe 30 seconds. Has anyone else had a moment like that and found a good way to get back on track without seeming totally lost?