"All the things that happen leading up to this fight, there's going to be a fight on Saturday night," said UFC president Dana White.
"We're almost there, this is almost over," he added of the pre-fight hype, which will no doubt help fill the UFC coffers.
The matchup pits the well-rounded St-Pierre (23-2) against the scrappy Diaz (27-8-0 with one no contest).
St-Pierre is hard to hit, avoiding 75.6 per cent of his opponent strikes (best among welterweights and third best in UFC history). And he has landed more significant strikes (1,048) and total strikes (2,188) than any UFC fighter.
The 31-year-old from Montreal also leads the UFC in takedowns with a 78.1 per cent accuracy rate. And when he gets you down, he keeps you there and punishes you. His 409 significant ground strikes are the most in UFC history. And in his last 15 fights, only one opponent has managed a reversal of a GSP dominant position.
The champion's takedown defence (88 per cent) is fourth best in UFC history.
St-Pierre has spent 45.3 per cent of his fights on top of his opponent and only 3.2 per cent on the bottom. The same numbers for Diaz are 11.3 and 15.3 per cent.
Put it together and you have a champion who can choose where the fight goes.
Diaz, 29, is a dangerous boxer who can score from distance — his 912 strikes landed at distance are the most in UFC/Strikeforce combined history.
The California fighter throws lots of punches, landing 8.28 significant strikes a minute in his last nine fights. No UFC fighter has matched that over the same time span.
And Diaz, like GSP a black belt in Brazilian jiu-jitsu, is a threat off his back. He has tried 20 serious submission attempts in his last 25 bouts, half of which from the bottom position. Four of those off his back earned tapouts.
At 60 per cent, Diaz's striking defence is slightly above the UFC average. But Carlos (The Natural Born Killer) Condit connected often in his win over Diaz last year, landing a UFC record 68 leg kicks and 151 significant strikes (fourth most by a welterweight in a single fight).
Both fighters are tough mentally.
The prickly Diaz is a pit bull, the kind of man you'd want at your back if you were backed into an alley facing a wave of attackers.
St-Pierre sticks to his game plan, taking the fight to where his opponent doesn't want to go.
Conventional wisdom has St-Pierre taking Diaz down, holding him there and beating him up. A grinding five-round decision that leaves both fighters marked, but Diaz worse for wear, could be in the cards.
"Control and the ground game is the way to win this fight," said former Canadian featherweight Mark (The Machine) Hominick.
"Diaz is a great boxer. He has a very specific style," added welterweight Nate (The Great) Marquardt, a longtime St-Pierre training partner. "Georges can change his styles a lot better than Diaz so I think Georges' game plan is going to be able to negate any kind of offence that Diaz has. Georges is going to be able to find the takedowns pretty easily and on the ground his defence is really good.
"So that will be where the fight happens, I believe, on the ground, inside Diaz's guard. So it's really going to depend on how aggressive Diaz is at going for the submission. He's very good at the armbar and there's a couple of positions Georges puts himself in where he could be susceptible to the armbar."
St-Pierre, while clearly antagonized by Diaz's often weird verbal assaults this week, rarely fights with emotion. He is all business in the cage.
The champion has been unstoppable in seven straight title defences since winning back the 170-pound title from Matt Serra in Montreal at UFC 83 in April 2008.
He made Josh Koscheck pay for his pre-fight taunts at UFC 124 with a stinging jab that sent Koscheck to hospital after in need of facial surgery.
He took Jon Fitch down seven times at UFC 87, Thiago Alves 10 times at UFC 100, Dan Hardy 11 times at UFC 111 and Condit seven times at UFC 154.
Against Jake Shields, a dangerous jiu-jitsu fighter, he landed just two takedowns at UFC 129 in what the champion admitted was an off night.
Fighters at GSP's Tristar gym, not surprisingly, are in the champion's corner.
"Georges is an animal, man," said lightweight Mike Ricci. "He is what he is. He doesn't stop. He's consistently winning, winning, winning. He's consistently working and preparing properly which is why he's winning. This time is no different. I don't expect this fight to be any different.
"It's a tough fight. You know Nick will score some points, that's for sure ... but he won't be able to get the upper hand on Georges for more than 10 seconds or 30 seconds out of a round."
"Georges is a beast at 170 pounds," added lightweight John (The Bull) Makdessi.
Calgary middleweight Nick (The Promise) Ring also picks a St-Pierre win.
"Georges has proven over and over and over he's too crafty for the competition. I think this will be no different."
Condit, who beat Diaz, also sees a GSP win but leaves Diaz some wiggle room.
"I think that he can (win)," he said of Diaz. "I'm not sure that he will."
St-Pierre's somewhat distant attitude — when not antagonized by Diaz — prior to this fight have led some to wonder how long the champion will continue. The champion has not looked happy this week, although some of that could be down to the weight cut.
A fight with No. 1 contender Jonny Hendricks, providing he beats Condit on Saturday, is next. And a lucrative super-fight with middleweight champion Anderson Silva looms in the distance.