PLYMOUTH, Mich. -- They are the best rivalry in women's sports right now, a perennial grudge match that exceeds anything the U.S. Olympic soccer or basketball teams have going when it comes to longevity or emotion or reliable high-stakes drama. And the players on the United States and Canadian women's national hockey teams all have their stories.

As veteran American defenseman Megan Bozek once famously said of facing Canada, "You know on that day you're trying to draw blood in the nicest way possible."

Nothing surpasses beating the other. And no loss hurts as much.

American winger Hilary Knight remembers losing a third-period lead against Canada at the 2014 Sochi Olympics and then trying not to look at the platters of gold medals before overtime started that the Americans were minutes away from winning -- and never got.

And yet, when Marie-Philip Poulin, who scored the overtime game winner that day for Canada, stood in the interview area Thursday at the IIHF Women's World Championships, she didn't mention that comeback in Russia as she looked ahead to playing the U.S. here Friday in yet another gold-medal match. Poulin talked instead about losing to the U.S. in seven of the past eight years these world championships have been played.

"It's been a while since we won one of these," Poulin said, "and we're on a mission now."

The U.S. routed surprise semifinalist Germany 11-0 on Thursday night, and Canada tore by Finland 4-0 earlier in the day to continue an amazing streak -- the two countries have now played each other in all 18 world championship finals since the tournament began in 1990.

Throw in the fact that they've played each other for the gold medal in four of the five times it has been awarded since women's hockey was added to the Winter Games in 1998 -- with the Americans' only win coming that year -- and you can see why the Canadian team said throughout the American team's threatened boycott of this event over contract issues with USA Hockey that it just wouldn't feel like a world championship if the Americans weren't here.

After a rocky 0-2 start to this tournament, Canada resembled its fearsome best against Finland on Thursday, avenging a 4-3 loss to the Finns in pool play last weekend. (How rare was it? Finland was 0-71 against Canada before that.)

The Finland loss came right after Canada's 2-0 opening loss to the Americans even though the U.S. players had just 48 hours to prepare for the tournament after their talks with USA Hockey dragged on for two weeks. "I don't think we've ever played better as a team. Ever," said Monique Lamoureux-Morando.

The Americans' fast-break offense -- and especially their top scoring line of Kendall Coyne, Brianna Decker and Knight -- has been sensational to watch, and even harder to stop. But Canada has steadied itself the past two games, defenseman Lauriane Rougeau says, by playing "freer" after a "nervous" start.

"We were just too tense and lacked confidence," Rougeau said. "What we need to do Friday is take it to the U.S. instead of letting them take it to us. It's always a battle when we play."

The rivalry has changed only slightly from when women's hockey debuted nearly 20 years ago, when American team leaders Cammi Granato and Karen Bye said their dislike of the Canadians ran so deep that they literally couldn't stand to even see the color red -- Canada's team color.

Once those Winter Games began, there was a story started by Canada head coach Shannon Miller that a U.S. player said something out of bounds to Canadian star Danielle Goyette during their first showdown in Nagano, only to have the indignant U.S. players object that what was said to Goyette wasn't about a family member at all -- it was profane, all right, but it definitely was not about a family member. So there.

There have been stories since -- some conflated, some not -- about one team supposedly stomping on the other team's logo in disrespect, or one team taking offense at how boorishly the other was celebrating one of its gold-medal wins.

Technically speaking, body checking isn't allowed in women's hockey, even though there is always a lot of contact. But the no-checking rule gets blurred, too, when the U.S. and Canada play. During a 2013 pre-Olympic exhibition game in Grand Forks, North Dakota, Jocelyne Lamoureux-Davidson objected to a hit by Canada's Brianne Jenner on Josephine Pucci, and smacked Jenner with a retaliatory check. Soon, Lamoureux-Davidson's twin sister, Monique, and everyone else jumped in and a full-scale brawl was underway.

In last Friday's tournament opener, what started as a little bump of shoulders in passing and some stick whacking here and there culminated with some scrums in front of the net and a few rabbit punches by the second period.

And a standing-room-only crowd of nearly 4,000 probably will see at least a bit of the same when the teams play for another world title Friday.

"We've gotten in numerous fights with them on tour -- not just scrums, fistfights. In front of the net, in the corners," American veteran Kelli Stack, who stands only 5-foot-5 and 137 pounds, said in an interview before this tournament. "One year, I had just come back from ACL surgery. I was just eight months back. One of my teammates got hit and we all just kind of jumped in and picked somebody and started fighting five-on-five. And, I mean, it was kinda funny, kinda not, you know?

"We don't usually take off our helmets unless they get ripped off. But most people do drop their gloves, just to grab the [face mask] cage. Makes it easier. I didn't do that, but as it was all going on, I was thinking, 'I just got back. What am I doing? Am I crazy?'"

Nah. As U.S. captain Meghan Duggan says, as rivalries go, this is the biggest.

"And as good a tournament as we've had so far, regardless of what we went through before, we also know we're not done," she said. "Whatever Canada brings, that's on them. But I know we'll be bringing our A-game."