On Sunday, two-time Olympic gold medallist Claressa Shields defeated unbeaten German Christina Hammer to unify the IBF, WBA, WBC and WBO middleweight titles. The contest was not just the most significant women’s fight in a generation but also the biggest test of the American’s professional career.Shields, who had three world titles before Sunday morning, spoke of the chance to fight for a million dollars one day. (For comparison sake, Mexican star Canelo Alvarez signed a five-year contract worth $365mn last year.) The fight against undefeated German Christina Hammer (24-1, 11 KOs), a Showtime main-event and supported on various digital platforms, thus had more on the line than just championships.

Shields won the middleweight gold in women’s boxing first Olympic showing in London 2012, mulled turning professional, before doubled her haul in Rio 2016, to go with her two World Championship golds. She collected three world titles in the next three years. Hammer, a German emigree from Kazakhstan and a world champion for nearly a decade, came into the fight the taller, longer and more experienced boxer. The 28-year-old German, who has been competing professionally since even before Shields even went to her first Olympics, took the fight because of the exposure.

After a cagey first round in which she assessed her opponent’s jab, Shields turned the fight into a rout with her effective aggression and sharp hands. She slipped, dodged and punished Hammer with stinging jabs and looping right hands. In all, the American landed 112 of 387 punches (29%), compared to 49 of 366 for the German (13%). The contest came close to being stopped in the eighth, when Shields knocked Hammer’s mouthpiece loose and rained a dozen unanswered shots to the head.

Shields now has natural match-ups in Cecilia Brækhus and Savannah Marshall. The former, Norwegian welterweight queen, is the only other woman boxer to hold all four major title belts in any division; the latter, an unbeaten British super middleweight, is the 1 in Shields’ 77-1 amateur record.