Alfredo Aceves and several players threw nasty punches when a fierce, full-scale brawl broke out in the ninth inning Saturday of Canada’s 10-3 romp over Mexico in the World Baseball Classic, a melee that also involved fans and set off skirmishes in the seats.

“Whoever says that we’re just here as an extra spring training game or we’re just here to say we represented our country and then go home obviously didn’t see how intense that game was and what it means to everybody that was involved,” Canadian slugger Justin Morneau said.

Multiple fights erupted after Canada’s Rene Tosoni was hit in the back by a pitch from Arnold Leon with the score 9-3 at Chase Field, home of the Arizona Diamondbacks. It quickly turned into a wild scene, as chaotic as any on a major league field in recent years.

Even when the fisticuffs ended, Canadian pitching coach Denis Boucher was hit in the face by a full water bottle thrown from the crowd. Canada shortstop Cale Iorg angrily threw the bottle back into the crowd.

Several police officers came onto the field trying to restore order, and there were a few skirmishes in the decidedly pro-Mexico crowd of 19,581. Seven players were ejected after umpires huddled, trying to sort out the frenzy.

There had already been several borderline plays on the bases when things got out of hand. A bunt hit by Chris Robinson heightened the tension — a WBC tiebreaker relies heavily on runs and the Canadians wanted to score again in the ninth. Third baseman Luis Cruz fielded Robinson’s bunt and seemed to tell Leon to hit the next batter.

Managers from both teams blamed the tiebreaking rule that uses run differential to determine what team moves on to the next round.

“It was just simply a misunderstanding,” Mexico manager Rick Renteria said. “In a normal setting, a normal professional setting I should say, a 9-3 bunt in that particular fashion would be kind of out of the ordinary.”

Right as the game resumed, someone in the crowd hurled a baseball that almost hit Canada first base coach Larry Walker in the head.

“That’s when I went out to the umpire and I said, ‘Another thing comes out, we’re going to pull our team off the field,” Canadian manager Ernie Whitt said.

The collision of WBC rules and the unwritten rules of the game led to the blowup, Renteria said.

“I think in just in the heat of the moment you lose sight of it,” he said, “and maybe that’s how it occurred.”

Whitt said WBC officials need to look at the tiebreaking rule.

“There’s got to be another method other than the scoring runs, running up the score on the opposing team,” he said. “No one likes that. That’s not the way baseball’s supposed to be played. There’s professionalism that we’re all accustomed to here in North America. And unfortunately teams are knocked out of the tournament because other teams run up the score on them. Unfortunately that’s what you have to deal with when you have that type of format.”

Morneau, Adrian Gonzalez and Joey Votto were among the big-name, high-priced stars playing in the game. The fight was exactly the kind of thing that must have made major league managers and general managers cringe at the thought of one of their players getting hurt in such a fracas.

“There’s a point you got to stand up for yourself,” said Morneau, a former MVP with the Minnesota Twins. “We got hit for playing the game, and that happens, but at the same time you got to stand up for yourself. You can’t just get pushed around.”

“Obviously everyone wishes it didn’t happen, but it happens in the game sometimes,” he said. ” I think we have all learned from being in the minor leagues that, especially in low-A ball, high-A ball, those things get real crazy. There’s not as much security. It starts to get out of control pretty bad, and I think you learn from that, you learn to keep your head on a swivel.”

Aceves was among four Mexican players thrown out — the angry Boston reliever was tossed to the ground by Philadelphia minor league outfielder Tyson Gillies during the height of the altercation, then rushed to rejoin the fray.

Also ejected were Leon, Oliver Perez and Eduardo Arredondo of Mexico and Tosoni, Pete Orr and Jay Johnson of Canada. A statement from organizers said tape of the incident would be reviewed for possible disciplinary action.

All in all, it was far from the worldwide goodwill that is supposed to accompany this competition, where players exchange team hats with opponents before the start of each game as a sign of sportsmanship.

A day earlier on the same field, Mexico posted an emotional 5-2 over the United States in a game without incident. Canada, meanwhile, absorbed an embarrassing 14-4 loss to Italy.

Mexico finished its Pool D play at 1-2. Canada is 1-1 going into a game Sunday against the United States.

Whitt said he hoped any decision on suspensions would take into account that Mexico has finished its pool play, while Canada has a big game remaining.

Canada scored four times in the first inning, and Mexico cut the lead to 4-3 with two runs in the fourth.

Karim Garcia, Edgar Gonzalez and pinch hitter Sebastian Valle started the inning with singles. Garcia tried to score from second on Valle’s single and was thrown out from center field by Gillies.

Robinson, the catcher, held on to the ball in a collision with Garcia down the third-base line. Garcia never did touch the plate.

Gil Velazquez followed with an RBI double and Arrendondo’s sacrifice fly cut Canada’s lead to one.

Robinson’s hard slide into second broke up a potential double play and allowed a run to score in a two-run seventh inning that put the Canadians ahead 7-3.

Morneau, who had four hits and drove in three runs, doubled in a run, then Michael Saunders walked and Robinson was hit in the foot by a pitch. With one out, pinch hitter Jimmy Van Ostrand grounded to second.

But Robinson took the legs out from Velazquez at shortstop to prevent the relay throw and a run scored.

“‘We want to play the game hard. We want to play it properly. You get an opportunity to help a team, help your teammates, by breaking up a double play or something, that’s something we do,” Robinson said.

All that led up to the ninth, with Mexico trailing badly and facing possible elimination despite the big win over the United States.

Robinson bunted because Canada wanted to widen the margin.

Two pitches came close to Tosoni and the next one hit him in the back. He dropped the bat and walked toward the mound.

When the players all rushed onto the field. Some just shoved, other threw wild haymakers. And just when it seemed things would calm down, more skirmishes ensued.

When the bottle was thrown from behind the Canadian dugout, one Canada player had to be restrained from going into the stands.

No player seemed to be hurt.

“I know the bodies kept moving everywhere but there was a lot more people holding people back than there was real action going on,” Renteria said, “as is always the case.”

As for his team, Whitt said, “You can’t hurt Canadians.”