Women's boxing landed on the biggest stage -- again -- and it delivered

Shields pours on the punches early en route to victory (0:43)

On her way to becoming the undisputed champ, Claressa Shields unleashes a flurry of punches in Round 1. (0:43)

Claressa Shields stood inside the ring in the middle of the O2 Arena in London on Saturday night, her eyes looking around at the British crowd that had just watched her assert why she is the greatest women's fighter of all time. She got emotional.

All that had happened, both in the ring and in the lead-up to it, may have been hitting her then. The enormity of what she had helped carry to fruition. For years now, since she was an amateur, really, Shields has been the face of women's boxing in the United States.

Almost every fight she's been in has had some level of history attached to it, and whether one likes or dislikes her, she and Katie Taylor have been the standard bearers for women in the sport over the past half-decade -- Taylor in Europe and Shields in America.

On Saturday night, in front of a sellout crowd, Shields and her opponent, Savannah Marshall, might have pushed their sport to another level.

"It's not just a special moment for me," Shields said. "It's a special moment for women's boxing."

For the second time this year, women's boxing landed on the biggest stage and outperformed the expectations of a highly anticipated fight. What Taylor and Amanda Serrano did for boxing at New York's Madison Square Garden back in April -- a hyped fight exceeding the most grandiose of hopes -- Shields and Marshall did the same in Great Britain.

The Shields-Marshall main event, which Shields won by unanimous decision to become the undisputed middleweight champion for the second time in her career, started at a rapid pace. Punches came fast from every direction for the majority of the two-minute rounds they fought. It didn't stop for the entirety of 20 minutes of action.

There was an atmosphere and energy set before the fight even began, from when the two fighters walked into the ring. That was clear from the get-go for the main event, when the O2 Arena fans belted out Neil Diamond's "Sweet Caroline" in unison before the co-main event and then when Marshall walked out to "Sweet Dreams (Are Made of This)" by the Eurythmics.

While Marshall might have lost the fight, the dreams of a generation of women boxers might be coming to fruition because of what she and Shields did. Even from a continent away, watching on television, one could feel the kinetic juice the arena had. The power. The passion. Madison Square Garden was rocking in April for Taylor-Serrano when they walked out for the main event. Shields-Marshall might have topped it.

"It's absolutely amazing that two women have sold out the O2. It's unbelievable." Savannah Marshall

It felt exactly like a high-energy sporting event should, including when Shields walked out moments after her British opponent -- embracing the moment and her role in all of this -- wearing trunks and gloves with the semblance of the American flag on them. At the top of the platform before her walk to the ring, which started with "The Champ is here" being said over and over again before she engaged in a choreographed dance, with backup dancers, to Yung Wun's "Tear It Up."

The moment was a classic, put on by a woman who knew she had to both bring the show and be the show. Then Shields stepped in the ring and delivered round after action-packed round to a crowd growing livelier and more anxious by the moment.

"It's absolutely amazing that two women have sold out the O2," Marshall said. "It's unbelievable."

For months now, Shields has been saying she believed this fight would show that women -- and women's boxing -- could sell. It's the second time she has headlined a card primarily with women's fighters on it -- the first, last year in her hometown of Flint, Michigan, had two male fights on it early in the card and was on a much smaller stage, albeit a pay-per-view event with her as a headliner, beating Marie-Eve Dicaire to become the undisputed junior middleweight champion.

There was no question Shields could sell at home, but going across the ocean as the A side to a fight in which she'd be the disliked one, the booed one, showed her staying power. Shields-Marshall became the worthy showcase women's boxing had hoped it would be and, frankly, needed it to be.

Alycia Baumgardner beats Mikaela Mayer by split decision

Alycia Baumgardner unifies the junior lightweight belts with a split-decision victory over Mikaela Mayer.

Mikaela Mayer-Alycia Baumgardner, the co-main event for the unified junior lightweight championship, had its own buzz as well. That fight could have potentially been a main event on its own. Instead, it became the No. 2 fight on the card and was close enough to be a split decision for Baumgardner. The fight could have been scored a draw or decided for either fighter. While it wasn't the slugfest many expected, it was a good, close, interesting fight. The type of fights women's boxing can build on, too.

Taylor-Serrano, a meeting of two future Hall of Famers, had set the expectation for big-time women's fights. Shields-Marshall showed women's boxing has the real chance to sustain, to be more than one big splash of boxing but a growing sport. That can be built on, fight after fight, big night after big night.

It showed what can happen -- and men in boxing should pay attention to this -- when top fighters do more than talk, but instead back up their chatter and social media sniping with actual signed contracts and fights worthy of setting aside a day to watch -- and not taking years to do it.

It's giving the fans what they want. It's building on the noise and following it up with tangible results. And it's what women's boxing has done to not only elevate itself within the sport, but what it should continue to do in order to truly thrive.