"Somebody asked me in the locker-room, 'How's Georges looking?' I said 'You know what? The last time I saw him like this is when he flattened Matt Serra at the same arena,'" Nurse told The Canadian Press.
"That was the (Serra) rematch and that's the last time I've seen him so nervous but itching to go as well, like 'I just want to get it done quick.'"
At UFC 83, it took St-Pierre just under two rounds to reclaim his 170-pound championship belt from Serra.
On Saturday night before a loud and proud Bell Centre crowd of 17,249, it was longer and bloodier. But it proved to be convincing.
Returning from a layoff of 18 months and 18 days after reconstructive knee surgery, a relentless St-Pierre won a five-round decision over Carlos (Natural Born Killer) Condit to unify the welterweight title.
They each won a $70,000 bonus cheque for fight of the night. St-Pierre, as the UFC's top pay-per-view draw, no doubt got millions more.
The judges scored it almost a shutout for St-Pierre: 49-46, 50-45, 50-45. But it was still a bruising, take-no-prisoners fight with St-Pierre pushing the pace from the opening. And the champion was in real danger in the third round.
St-Pierre, who said he got his fire back after such a lengthy layoff, called the fight "a blast."
"I was getting hurt, it was painful but I had a lot of fun. I love my job," he added.
St-Pierre (23-2) said his knee felt fine but being away from the cage for so long, he forgot the full-bore fighting experience.
"The suffering, this feeling of not giving up," he said.
He got a crash course in remembering Saturday. St-Pierre walked into the news conference in a three-piece suit, holding an ice bag to his head.
He had a fat lip, cuts under both eyes and on the bridge of his nose, and a thick band of red abrasions and bumps on his shaved head that looked like someone had applied a giant vise to his forehead.
"Before I put the ice on, my head had the shape of an American football," St-Pierre said with a laugh. "That's why I put some ice on. I hope it gets better with time."
The right side of Condit's face looked like someone had taken a screwdriver to his temple — it was actually a St-Pierre elbow — and then run a grater down his cheek.
The 31-year-old St-Pierre had not fought since April 2011 and underwent knee surgery in December after an injury in training. Condit (28-6) won the interim title during his absence, defeating Nick Diaz in February.
While St. Pierre said he felt some ring rust, he essentially looked as good as new against a difficult opponent who seemed to be peaking at the right time.
"It's huge. Tonight was a big, big night as far as his legacy is concerned," UFC president Dana White said of St-Pierre.
The Montreal native has now won 10 straight and not lost in more than five years.
His legacy could be further defined in the next year. The GSP win likely means a super-fight showdown with middleweight (185-pound) champion Anderson Silva.
Saturday's win moved St-Pierre into a tie with Matt Hughes for most successful title defences (seven) behind only Silva (10).
The first two rounds went to GSP but Condit threatened in the third, using a head kick to put the champion in deep waters for perhaps the first time in his seven title defences.
"Credit to Carlos, he definitely gave me my toughest fight," said St-Pierre, who rated the contest up there with his gruelling 2008 win over Jon Fitch — another bruising five-round encounter but not one where he was in danger of losing.
St-Pierre consolidated his lead with takedowns as the fight wore. St-Pierre dumped Condit seven times in eight tries over the 25 minutes to stretch his career UFC takedown record to 75.
Condit worked a prickly, active game from the bottom but could not stop St-Pierre's dominant top game.
"Obviously that's not where I wanted to be, I didn't want to be under Georges taking elbows," said the game challenger.
Ultimately GSP's wrestling skills and ability to resist Condit's submission attempts on the ground won the day in what was an entertaining fight. St-Pierre controlled the contest.
"I'm happy, I gave everything I had. I left everything I had in the Octagon," he told the post-fight news conference, with Condit nodding his head in agreement.
The strategy against Condit was to push the pace and "soften him up those first two rounds," said Nurse. "And then when you see fit, take him down and soften him up" some more.
So St-Pierre came out, took the centre of the Octagon and stalked Condit. Many had given Condit the striking edge going into the fight, but St-Pierre walked away with no less than a tie in striking.
The first takedown came within two minutes, with St-Pierre looking to score from above in Condit's guard. Condit, comfortable fighting off his back, looked cool but took some damage.
Condit was cut above the right eye by an elbow near the end of the round.
Condit knocked St-Pierre down with a head kick early in the third and swarmed him. GSP weathered a dangerous storm and finally got back up, his face leaking blood. He then dumped Condit on the ground and won the rest of the round.
"I thought I had him there," Condit said of the kick.
"Georges showed again why he's the champion," said Nurse, admitting his heart was in his mouth at that point of the fight. "He came back, got out of that situation and turned it around and took back charge of the fight."
St-Pierre spent considerable time on his back with jiu-jitsu coach John Danaher in advance of the fight, just for that eventuality. The move that saved him was slicing a knee through the legs, working his way back into a wrestling position and then getting up off the fence.
"It wasn't necessarily the most exciting thing to do in training camp but he did it and it paid off," Nurse said of the jiu-jitsu prep.
Head coach Firas Zahabi said St-Pierre proved he could stand with a powerful striker, with the exception of the "nasty head kick."
"Georges made a grave mistake, that I don't think he will make again," said Zahabi. "I told him many times to watch the head kick ... I don't think he realized how dangerous it was until he got kicked. It's something I reminded him of every round after that."
The fast pace was shown by the fact St-Pierre held a 16-2 edge in significant strikes in the first round and 16-9 in the second, according to FightMetric which tracks such statistics. Condit won the third 16-9 before St-Pierre regained his edge to lead 9-3 in the fourth and 21-6 in the fifth.
While the significant striking tally was 71-36 in St-Pierre's favour, Condit had a 190-172 edge in total strikes — significant or not.
There were questions going into the fight. Would it be business as usual for St-Pierre? Or was the returning champ ripe for the taking?
St-Pierre proved willing and able.
White has some options if he needs more time to settle the ground rules for a Silva-GSP super-fight.
In Saturday's co-main event, Johny (Bigg Rigg) Hendricks knocked out Martin (The Hitman) Kampmann in 46 seconds in a battle of welterweight contenders. It was a slightly longer replay of his 12-second KO of Fitch.
Hendricks, a former two-time NCAA wrestling champion, has now won five straight and stands at the top of the 170-pound contender line.
"I made my case," Hendricks (14-1) said of his title aspirations.
"I'm a wrestler and I can knock people out. That's pretty sweet, huh?" he added, drawing laughs.
Said White: "He looked damn good tonight."
The 37-year-old Silva met the media before the card started, declaring his interest in meeting GSP somewhere between their two weight classes.
"I need to take some vacation and think about it," St-Pierre said of the super-fight.
White is willing to give him the time.
"I'm sure he feels like he got hit by a bus right now. I'm not even going to talk to him about it for a couple of weeks."
Still he's confident it will happen.
"I think we can get it done," he said.
White has targeted May with Toronto's Rogers Centre, Cowboys Stadium in Dallas or a Brazilian soccer stadium as possible venues.
"Dallas, Texas, probably sounds better for everybody because it's neutral," said White, who would be trying to sell 100,000 seats there.
Silva, who was watching cageside, has two fights left on his contract. He wants GSP next and then "maybe" light-heavyweight champion Jon (Bones) Jones.
"It will happen," White said of Jones. "The fun thing about Anderson Silva being the best fighter in the world is that he falls right in the middle of No. 2 and No. 3 pound-for-pound best fighters in the world. I think we can look forward to some fights."
White sees Silva fighting GSP, defending his title a few times before fighting, then taking on Jones. But he would not rule out St-Pierre making another title defence before meeting Silva.
Ironing out the details is what he does, White said.
"I want Anderson Silva to love this fight and want this fight. I want Georges to love this fight and want it," he said.
Both men will make a huge payday, he added. "That's a no-brainer."
The St-Pierre camp will have plenty to say on the details. GSP looks small compared to the lanky Condit and the supersized Silva will have a further edge no matter what number he has to make on weigh-in day.
Silva talked of fighting at 177-78 pounds. But St-Pierre said if that was the number, Silva would probably still outweigh him 225-230 to 185 on fight night.
"He's a big guy, he's a very big guy," he said.
White later disputed GSP's estimate of Silva's weight.
But St-Pierre clearly believes Silva also appears to have an easier time moving up and down in weight. St-Pierre said his body does not adjust nearly as well.
"At the end of the day if Anderson Silva wants to fight him, let him come to 170 — we never say no," said Zahabi. "If he wants Georges to come up to 185, then we've got to weigh our risks and make the risks worth it. And that's going to involve negotiations with the UFC and all parties."
Look for the fight to happen between their weights.
St-Pierre may be the smaller man but he has a huge heart and an ample toolbox.
"I use my body the best I can," said St-Pierre."I don't have the knockout power of a Rampage Jackson. I don't have maybe the athletic ability of a Jon Jones, I don't have the accuracy of an Anderson Silva or the wrestling of a Chael Sonnen. But I use my body, with the tools I have, the best as I can and that's why I win fights.
"It's not always about the muscle, it's the mind."
St-Pierre brought his parents into the Octagon after the fight. "If I'm here tonight, it's because of them."
He also gave his championship belt for the second straight fight to Zahabi as thanks.