One funny moment came when Thiago Alves was trying to make weight at 171 pounds. He came in half-a-pound heavy so they raise the towel and drop the underwear. He was still too heavy and had to hit the treadmill.
The main event will match Chael Sonnen and Anderson Silva at 185 pounds.
The man who is the driving force behind the UFC is President Dana White.
"All I have to say before we kick this thing off is holy sh*t," said White.
White is unlike the head of any other major sport.
"Dana is more of a blue-collar commissioner than any other sport or any other business you're going to find. He speaks from the heart, he shoots from the hip. You know what you see is what you get from Dana," said UFC welterweight Jon Fitch.
White is bold, he's brash and he taken a sport that John McCain once described as human cockfighting and turned it into a billion dollar operation.
The UFC was on life support when White took over 10 years ago. Now, it's mainstream.
"I don't care what country you come from, what language you speak, what color you are, we're all human beings and fighting is in our DNA. We get it and we like it. You know you're going to have some people out there that might not be fight fans, but there's plenty of people who are," said White.
Critics of the UFC claim the sport is too barbaric, uncivilized, way more dangerous than boxing. White's a former boxer. He says no way.
"This is much safer than boxing. In the almost 20-year history of Ultimate Fighting Championship, there's never been a death or serious injury," said White.
The UFC is holding its first show in the Bay Area this Saturday night. They're expecting more than 15,000 fans and hundreds of thousands watching on Pay-Per-View.
And if White is right, the best is yet to come.
"This is going to be the biggest sport in the world. We've taken this thing global. We've been to England, Ireland, Germany, Abu Dhabi, we've been to Australia and now we've just opened up China. We're going to India and we're going to South Korea. So we've got big plans over the next five years," said White.
The growth of this sport is mind-blowing.