Canada High: Mikaela Mayer Wins Unified Super Welterweight Crown

Courtesy: Vitor Munhoz/Eye Of The Tiger

Canada High: Mikaela Mayer Wins Unified Super Welterweight Crown

Mayer is now a three-weight world champion

MONTREAL, Canada (Oct. 30, 2025) — Mikaela Mayer traveled to enemy territory and is coming back to America as a three-belt world champion.

Mayer defeated Canada's Mary Spencer via one-sided unanimous (100-90 and 98-92 2x) to capture the WBA, WBC, and WBO super welterweight world titles Thursday evening at Montreal Casino in Montreal, Canada.

Mayer (22-2, 5 KOs), who is still the reigning WBO welterweight queen, is now a three-weight world champion.

Though the smaller fighter on paper, Mayer looked and fought like the bigger woman inside the ring, pressing forward behind a stiff jab before crouching low to connect with right hands.

Mayer established the straight right early, then began landing left hooks to keep Spencer (10-3, 6 KOs) on the defensive. The former champ spent much of the fight on the back foot, circling Mayer to find opportunities to connect. She was unable to stifle Mayer’s constant pressure down the stretch and was buzzed in the ninth and 10th rounds. 

Mayer said, “Usually, I’m the taller fighter. But because I’m usually the taller fighter, I also know how to beat me. And it’s never good when you’re the taller fighter and you let the other fighter get underneath.

“So, I knew I had to come up underneath Mary Spencer and just come over the top with the big hooks. That’s what we trained for, and you saw me towards the last three rounds of the fight, really landing those big right and left hooks to the head.

“I think the most important thing is I have options. That's great in boxing. You always want options. I came off two years where my career kind of took a left turn. I had to navigate my way back to this position. So having options is definitely a blessing.

“I’ll have to go back and go over things with my team. I would love to defend both belts. I can go back to 147, become undisputed there, and maybe come back up and defend at 154.”

Undercard Results:

Super Middleweight: Wilkens Mathieu (15-0, 10 KOs) UD 10 Shakeel Phinn (27-4-2, 17 KOs). Scores: 99-90 & 98-91 2x. Mathieu wins vacant NABF and WBC Continental Americas titles.

Junior Welterweight: Arthur Biyarslanov (20-0, 16 KOs) UD 10 Sergey Lipinets (18-5-1, 13 KOs). Scores: 97-92, 99-90 and 96-93. Biyarslanov defends NABF title.

Light Heavyweight: Mehmet Unal (14-0, 12 KOs) TKO 1 Ralfs Vilcans (18-3, 7 KOs). Time of stoppage: 2:44. Unal retains WBC Continental Americas title.

Welterweight: Christopher Guerrero (16-0, 9 KOs) UD 10 Williams Andres Herrera (17-5, 7 KOs), Scores: 97-93, 99-91 and 98-92. Guerrero retains WBC Continental Americas title. 

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