Claressa Shields is now a three-time undisputed champion, the first person to achieve such a feat in either men’s or women’s boxing. Shields defeated Savannah Marshall (12-1, 10 KOs) via unanimous decision to unify all the belts at middleweight in an action-packed slugfest.

Marshall’s plans were clear: overwhelm Shields, push her against the ropes and land power shots. But Shields, who possessed more speed and accuracy, countered Marshall’s constant pressure with rights and lefts that were thrown with all of her strength.

Shields (13-0, 2 KOs) earned the win with scores of 96-94 and 97-93 2x, cards that demonstrated her superiority inside the ring.

“I bit down in every round,” Shields said. “In every round, it felt like she would hit me with a big shot, and I would hit her with a big shot. If she hit me to the body, I’d punch her to the body. But I know that I did the most work today and that I was winning with my inside combinations.”

In undercard action:

Welterweights: Lauren Price (2-0, 1 KOs) scored a fourth-round technical knockout against Timea Belik (6-7, 2 KOs). Time of stoppage: 1:18.

Lightweights: Caroline Dubois (4-0, 3 KOs)retained her undefeated record via fifth-round TKO against Milena Koleva (10-15-1, 4 KOs). Time of stoppage: 1:53.

Featherweights: Karriss Artingstall (2-0) scored a decision win against Marina Sakharov (5-17-2, 3 KOs). Score: 60-54.