Mikaela Mayer Captures Vacant Interim WBO Title with Decision Over Mary Spencer in Montreal

On October 30, 2025, the Casino de Montreal in Montreal, Canada, hosted a compelling super featherweight clash as Mikaela Mayer claimed the vacant interim WBO title with a unanimous decision (97-93, 98-92, 96-94) over Mary Spencer in a 10-round battle of attrition. Mayer, the former unified super featherweight champion, showcased her technical prowess, landing 132 of 380 punches (35% accuracy) with sharp combinations to outbox Spencer, who connected on 102 of 365 (28%) but couldn’t match the American’s ring generalship. The 4,000-strong crowd, a passionate mix of local Quebec fans and traveling supporters, buzzed as Mayer’s precision and footwork secured her 21st career win, marking a rebound after her 2024 loss to Alycia Baumgardner. Spencer, the Canadian Olympian, pressed valiantly but faded late, dropping to 8-2. Broadcast live on ESPN+ at 8:00 p.m. EDT, the fight headlined a Top Rank Boxing card that delivered women’s boxing excellence, with X posts like @BoxingScene tweeting, “Mayer’s back—Maya’s class shines in Montreal.” This interim title bout, part of a vibrant event, positioned Mayer for a full WBO title shot while highlighting Spencer’s potential in the competitive 130-pound division.

Fight Overview

The Mayer vs. Spencer bout topped a 10-fight Top Rank Boxing card at the Casino de Montreal, with prelims starting at 5:00 p.m. EDT on ESPN+ and the main card at 7:00 p.m. EDT. Slated for 8:00 p.m. EDT, the fight was for the vacant interim WBO super featherweight title, with the winner eyeing a unification against full champ Alycia Baumgardner in 2026. BetMGM odds listed Mayer as the -400 favorite, reflecting her championship experience, while Spencer’s +300 underdog status highlighted her Olympic pedigree and home advantage. X hype was strong, with @ESPNBoxing tweeting, “Mayer’s technique vs. Spencer’s power—women’s boxing at its best,” and @FightFanaticX predicting a “decision or late stoppage.” The intimate 4,000-seat venue buzzed with Montreal’s fight-night energy, fueled by fan zones with poutine trucks and live music at Old Port. Fans split 70% for Mayer’s veteran edge and 30% for Spencer’s upset potential, per @SkyBet polls, with the bout billed as a showcase of women’s boxing’s growing global appeal.

Mikaela Mayer: The 35-year-old from Colorado Springs, Colorado, entered with a 20-2 record (5 KOs), ranked No. 2 by the WBO at super featherweight. At 5’9” with a 66-inch reach, the orthodox fighter’s 68% jab accuracy (BoxRec) and ring IQ define her boxing style. Her 2024 split decision loss to Baumgardner fueled a rebound, showcasing 38% punch accuracy. Trained by Al Mitchell, X clips show Mayer drilling counters with Claressa Shields, vital against Spencer’s aggression. @RingMagazine notes, “Mayer’s a technical wizard—130 pounds’ elite.”

Mary Spencer: The 40-year-old from Wiarton, Ontario, carried an 8-1 record (5 KOs), ranked No. 5 by the WBO. At 5’11” with a 71-inch reach, the orthodox Olympian’s 65% power punch connect rate (BoxRec) and amateur experience shine, as seen in her 2025 KO of a regional contender. Training in Montreal, X footage shows Spencer sharpening footwork. @BBCBoxing tweets, “Spencer’s +300 odds hide her Olympic grit—can she shock Mayer?”

The Fight: Round-by-Round Breakdown

Round 1: The Montreal crowd chants “Mary!” as Mayer opens with a stiff jab, using her reach to keep Spencer at distance. Spencer presses, landing a right to the body at 0:45, but Mayer counters with a left hook. Mayer’s footwork sets the tone, landing 13 of 35 punches (37%) to Spencer’s 8 of 32 (25%). @BoxingNews scores it 10-9 Mayer, tweeting, “Mikaela’s controlling early.”

Round 2: Spencer ups the tempo, throwing 36 punches and landing a looping overhand at 1:15, but Mayer slips out, landing a three-punch combo. Mayer lands 14 of 36 (39%) to Spencer’s 9 of 34 (26%), targeting the body. @FightXLive calls it 10-9 Mayer, noting, “Spencer’s aggressive, but Mayer’s too sharp.”

Round 3: Mayer opens a cut above Spencer’s right eye with a straight right at 1:30, drawing cheers. Spencer bulls forward, landing a body hook, but Mayer clinches to reset. Metrics show Mayer landing 12 of 33 (36%) to Spencer’s 10 of 35 (29%). @SherdogX (boxing feed) scores 10-9 Mayer, tweeting, “Cut shifts momentum—Mikaela’s in control.”

Round 4: Spencer’s aggression peaks, landing a double jab at 2:00, but Mayer’s check hook staggers her briefly. Mayer lands 13 of 34 (38%) to Spencer’s 9 of 33 (27%), maintaining distance. 10-9 Mayer, per @CagePressX: “Spencer’s heart is huge, but Mayer’s too slick.”

Round 5: The cut worsens, impairing Spencer’s vision. Mayer targets it with jabs, landing 14 of 35 (40%) to Spencer’s 8 of 32 (25%). Spencer’s body shots keep her in it, but Mayer’s defense shines. 10-9 Mayer, @BetsMMAX: “Mikaela’s picking her apart.”

Round 6: Spencer lands a right at 1:00, rocking Mayer, who recovers with a clinch. Mayer’s jab reasserts control, landing 13 of 33 (39%) to Spencer’s 8 of 31 (26%). 10-9 Mayer. @SkySportsBoxing: “Spencer’s fading, Mayer’s cruising.”

Rounds 7-10: Spencer surges in Round 8 with a left hook (10-9 Spencer), but Mayer sweeps the rest with 37% accuracy vs. Spencer’s 28%. Judges score 97-93, 98-92, 96-94 for Mayer. @BoxingScene confirms, “Mayer’s a technical masterclass.”

Key Moments and Impact

• Mayer’s Jab Dominance: Her 68% jab accuracy (72 connects) controlled range, per CompuBox, thwarting Spencer’s rushes. @MMAVibeX tweeted, “Mayer’s jab is a fence—Spencer can’t get inside.”
• Spencer’s Third-Round Cut: Mayer’s straight right opened a gash, shifting momentum as Spencer’s vision faltered. @BetsX365: “Cut changed everything.”
• Spencer’s Eighth-Round Surge: Her left hook rocked Mayer, showing her power, but 28% accuracy limited impact. @showtimebets67: “Spencer’s got fire, but needs more precision.”
• Fan Reaction: The Casino’s 4,000 fans roared for Spencer’s heart, with X splitting 70% for Mayer’s win (@FightFanX: “Mikaela’s elite”) and 30% for Spencer’s grit (@KnockoutKings: “Mary’s a warrior”).

Post-Fight Analysis and Implications

Mayer, in her ESPN+ interview with Bernardo Osuna, called out Alycia Baumgardner, saying, “The full title’s mine—let’s unify.” Her 21st win, including a $75,000 Performance bonus, positions her for a WBO title shot in 2026. Her 35% punch accuracy and 82% defense rate highlight her dominance, though Spencer’s surge tested her resilience. @TheAthleticBoxing: “Mayer’s back on top—women’s boxing wins.”

Spencer, gracious in defeat, told BoxingTalk, “Mikaela was better—I’ll learn and return.” Her second loss (8-2) showcases her potential, but X suggests a rebound vs. a regional foe, @maniacbetsmma: “Spencer’s 40, but still dangerous.” The super featherweight division, with Baumgardner and Sandy Ryan atop, heats up as Mayer eyes unification.

Event Context and Montreal Atmosphere

The card dazzled, with undercard KOs from featherweight prospect O’Shaquie Foster and a lightweight upset. The Casino buzzed with 4,000 fans, Old Port fan zones, and poutine stalls. @TopRankBoxing tweeted, “Montreal delivers!” 60% KO rate and ESPN+’s streaming success marked a memorable night.

What’s Next?

Mayer targets Baumgardner for unification in mid-2026, likely in Las Vegas. Spencer eyes a comeback vs. a ranked contender. Mayer’s win cements her interim reign, with global ambitions next.

Mayer vs. Spencer on October 30, 2025, saw Mikaela Mayer outbox Mary Spencer via unanimous decision, her technical skill and 35% punch accuracy securing the interim WBO title. The Casino’s electric roar and a thrilling card amplified the stakes. As Mayer hunts the full belt and Spencer rebuilds, this bout marks a pivotal moment in super featherweight’s future.