The 155-pounder from London, Ont., won his UFC debut against Fisher via split decision at UFC 58 in March 2006. An injury replacement for fellow American Kenny Florian, Fisher took the fight on short notice and had to lose 20 pounds in two days.
In June 2007, a fresh Fisher convincingly won the rematch in the main event of a televised card in what was judged fight of the night.
"I haven't gone to one signing or event or anything since 2007 without having at least one person bring those fights up to me and say 'Those are my favourite fights.' Or a lot of people say 'Those are the fights that made me an MMA fan,' and stuff like that," said Stout.
"So it's a pretty cool thing we have and I'm really excited we're getting to do the rubber match."
Their fight Friday is the co-main event of a televised card at the Revel Casino in Atlantic City, N.J. The featured bout is a lightweight clash between Gray (The Bully) Maynard and Clay (The Carpenter) Guida.
Both the 28-year-old Stout (18-7-1) and the 36-year-old Fisher (25-8) are coming off losses to Thiago Tavares in Brazil.
But prior to that, the two fighters had been travelling in different directions.
Stout had won four of his last five, including a highlight-reel knockout of Yves Edwards at UFC 131 in Vancouver in June 2011, before losing a unanimous decision to Tavares at UFC 142 in January. Fisher had lost three of his last four before suffering a second-round KO by Tavares at UFC 134 last August.
Stout is 6-6 in the UFC while Fisher is 9-7. But both men are the kind of Energizer Bunny fighters that the UFC loves so much. It's rare either puts on a poor show, win or lose. The two have combined for seven announced bonus cheques, with five going to Stout and two to Fisher.
Despite their fighting ties, the two are not close. When they met in the hallway earlier this week, they shook hands but didn't talk.
"We don't really speak," said Stout. "There's definitely mutual respect. ... Maybe we'll have a beer or something afterwards, especially after this trilogy. But we don't go back and forth on Facebook or Twitter or anything like that.""
Stout said his camp had asked to fight Fisher again.
"It just seemed like the right time to do it," he said. "He was coming off a loss to the same opponent I was. It seemed like over the years any other time that we had thought about doing it, either he was coming off a win and I was coming off a loss or the other way around."
The Stout and Fisher battles are memorable because neither man yields an inch.
In the first, Fisher had the early upper hand and put Stout down three times in the first round. But Stout came back against a clearly fatigued Fisher, who was so tired that his mouthpiece fell out three times in the third round. A bloody Fisher never stopped throwing punches, however.
Stout, who was 21 at the time, got a 29-28, 29-28, 28-29 decision at the Mandalay Bay Events Center in Las Vegas.
"It was just one of those nights where I felt really good going in there," recalled Stout.
"One of the best nights of my life," he added.
Friends and family were there to see his successful debut. And friend and training partner Mark (The Machine) Hominick also won on the night.
It helped that Stout had trained briefly with Fisher a few months before the bout. And he had fought nine times in the previous two years, winning eight with one draw.
"That was also a big confidence booster," he said.
Stout's fitness also paid off. The young fighter had lost a bout earlier in the career because of fatigue and never forgot it.
"It was the worst feeling, knowing that I lost not because I wasn't the better fighter but because I wasn't in better shape,'' he said. "So I just made a promise to myself that I would never let that happen again."
The rematch did not go as well for the then 23-year-old Canadian, who was outgunned by the faster, crisper Fisher.
"I think I might have been a little overconfident in it," said Stout.
The Canadian also believes he did not prepare as well as he could for the hard-nosed southpaw.
"I don't think I went in with enough of a game plan in that fight. I thought 'OK, I've already beaten him. I'm going to beat him again.' I was still young. I just didn't think it through as much as I should have."
Fisher came out fast and rocked Stout several times throughout the second fight, which was contested entirely on the feet. Stout tried to rally and cut Fisher around the face.
It looked like someone had taken a screwdriver to Fisher's face. By the end of the first round, the left side of his face and his mutton chop sideburns were masked by blood.
But Fisher was winning.
"He came out really, I think, the best he's ever looked," said Stout. "Still to this day, I don't think I've ever seen him come on stronger, keep that pace and look as physically as big and strong as he was that night.
"That's really the Spencer Fisher that I've been preparing for this fight. Best case scenario Spencer Fisher and even more so than that."
Fisher, who says this may be his last fight, says Stout brings out the best in him. And vice-versa.
"For some reasons, put the two of us in the cage together, it's a recipe for fireworks definitely."
Fisher, however, has been frustrated by injury in recent years, including a detached retina and torn shoulder.
"I think it's just years of wear and tear on his body ... It's hard to keep up this pace," said Stout, who has modified his own training and added yoga and pool workouts in a bid to save his body.
Fisher has said he believes he can hit Stout, whom he says has taken more blows in his recent fights.
Surprisingly, Stout agrees with the second half of the statement.
"There's been a few fights in my recent fight history that I haven't moved my head enough,'' he said. "It's been something I've been working on trying to change. I think he's going to have a lot harder time hitting me than he thinks."
The Tavares fight in Brazil was the first for Stout since the death of Shawn Tompkins, his trainer, friend and brother-in-law. Stout had actually put off an earlier bout because he didn't think he was ready to go without Tompkins.
Stout trained for this fight mostly at the gym he co-owns in London, although he spent some time in Las Vegas.
He has a new conditioning coach in Carter Walls and says he is trying to train smarter. He will also have noted striking coach Marc DellaGrotte in his corner.
"Me and Marc have been friends for a long time," Stout said. "He and Shawn were also very close. They had a lot of mutual respect for each other. And whenever Shawn would get pissed off at me and tell me to go train with somebody else, he'd also say 'Go train with Marc DellaGrotte.'
"I know for a fact if there's anyone else out there he'd want in my corner, it would be Marc DellaGrotte."
Stout and Tompkins were always on the same wavelength. During fights, Tompkins would yell out an instruction and Stout would automatically put it into action.
The fighter says he trusts DellaGrotte and likes his training style and positive energy.
"I need somebody who knows the game inside and out, that I can trust. Which is also something I really had with Shawn. That trust is part of what made our relationship so strong when it came to fighting.
"I'm not saying it's going to be the same (with Marc) but it's something that we can work on developing and I think it's going to be great for both me and Marc."