PHOENIX — A fierce brawl that saw Alfredo Aceves and several players throw nasty punches erupted Saturday in the ninth inning of Canada's 10-3 romp over Mexico at the World Baseball Classic in a melee that also involved fans.

Multiple fights broke out 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.

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

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

Aceves was among four Mexican players thrown out — the angry Boston reliever was tossed to the ground by Philadelphia minor-league outfielder Tyson Gillies.

Also ejected were Oliver Perez (of the Mariners), Leon and Eduardo Arredondo of Mexico and Tosoni, Pete Orr and Jay Johnson of Canada.

Rivera: final season

TAMPA, Fla. — Saying he made the decision before arriving at spring training, Mariano Rivera announced he will retire at the end of the season and hopes to cap his record-setting career by winning another World Series with the New York Yankees.

With the entire Yankees team looking on — including longtime teammates Derek Jeter and Andy Pettitte — Rivera said he knew the time was right for his decision.

"I have just a few bullets left," he said.

He then made his first game appearance since April 30, throwing a 1-2-3 fifth inning against Atlanta.

Earlier, Jeter singled sharply to left field on his first pitch since breaking an ankle last fall in the AL Championship Series.

Notes

• Carlos Santana homered, Robinson Cano had three hits and the Dominican Republic beat Spain 6-3 in San Juan, Puerto Rico. Mike Aviles drove in three runs as Puerto Rico beat Venezuela 6-3. Puerto Rico and the Dominican Republic both advanced to the second round.

• Yasmany Tomas hit a three-run homer in the fourth inning, helping Cuba rout Taiwan 14-0 in Tokyo.

• Albert Pujols hit his first spring-training home run during the L.A. Angels' 8-6 loss to Colorado in Tempe, Ariz.