For five years, Karsten Warholm’s 45.94-second world record had stood as the ultimate benchmark in the 400m hurdles. That mark finally fell in Zurich on August 27, when Brazil’s Alison dos Santos delivered a 45.80-second run. He became the second man to break the 46-second barrier after Warholm, and also took 0.14 seconds off his record. Now, seeing Dos Santos produce such a historic performance has also left American sprint star Noah Lyles impressed.

“Alison Breaking the World Record Just for Fun,” Lyles wrote on X after seeing Dos Santos rewrite the record books.

Dos Santos had already given Warholm’s record a warning signal just four days earlier at the Silesia Diamond League in Poland. The Brazilian ran 46.43 seconds to beat the Norwegian in a close battle, setting up another highly anticipated meeting between the two rivals in Zurich on Thursday.

This time, however, the race unfolded very differently. Warholm had the advantage of the stagger at the start, but Dos Santos immediately began closing the gap. The Brazilian attacked from the opening metres and quickly moved closer to the former world record holder.

“I was actually opening pretty hard,” Warholm said after the race.

Yet Dos Santos was coming fast. Warholm could already feel the Brazilian near him at the first hurdle. By around the fourth hurdle, he could see Dos Santos closing in, something the Norwegian said was unusual for him. Then, by halfway, Dos Santos had erased the stagger completely. 

The scale of Dos Santos’ performance was even clearer when compared with his previous personal best. The Brazilian had entered the race with a best of 46.29 seconds, the mark he ran to win the 2022 world title. In Zurich, he suddenly went 0.49 seconds faster. 

“My first reaction is honestly that I was a bit shocked,” Warholm admitted about Dos Santos breaking his record.

The Norwegian said he had not expected Dos Santos to produce such a performance, especially after their close race in Poland only four days earlier. Yet even as he watched his five-year reign come to an end, Warholm was quick to recognize what his rival had accomplished.

“Alison is a great competitor, a really, really fast hurdler,” Warholm said. “I gotta say congratulations and give him the respect that is deserved.”

The 400m hurdles rivalry between Warholm and Dos Santos has evolved into one that fans will relish for ages. However, for Dos Santos, it was quite a journey since his 2021 heartbreak.

How Dos Santos Overcame a 5-year Heartbreak Since Warholm Overshadowed Him

Alison Dos Santos felt on top of the world after breaking Karsten Warholm’s Record on Thursday. For the Brazilian, the story of this achievement had its seed planted at the 2021 Tokyo Olympics.

Dos Santos won bronze in the 300m hurdles with a 46.72-second run, a time that would have broken the world record that had stood for 29 years. Unfortunately for him, 33 days before the event, Warholm had already done that by breaking Kevin Young’s 46.78 world record run at the 1992 Olympics in Barcelona, improving it to 46.70.

After Thursday’s heroics, Dos Santos looked back at the moment.

“The memory that I have right now is from Tokyo in 2021,” Dos Santos told Flotrack after his record-breaking run. “I was able to run faster than the previous world record, but I got third (in 46.72). And I promise you, that hurt so bad. I was like, I never want to experience that again, break a world record and not be the first one (to cross the finish line).”

That feeling of hurt compounded as Warholm, who claimed the world title in 2017 and 2019, recorded one of the greatest performances in the history of the event, running 45.94 seconds, breaking his own record and becoming the first man to dip under 46 seconds.

A year later, the game changed. At the 2022 World Championships in Eugene, Dos Santos captured his first world title with a winning time of 46.29 seconds. Rai Benjamin took silver in 46.89, while Trevor Bassitt won bronze. Warholm, who had been dealing with injury problems that season, was unable to challenge for the podium. The victory marked Dos Santos’ arrival as a champion in his own right rather than simply another athlete chasing Warholm.

His 46.29 also became his personal best and remained the fastest time of his career for several years. The 2024 Paris Olympics added another chapter to the rivalry, although Rai Benjamin once again stood between the two. Benjamin won Olympic gold in 46.46 seconds, with Warholm taking silver in 47.06 and Dos Santos claiming bronze in 47.26. For Dos Santos, it was his second Olympic bronze after his third-place finish in Tokyo.

The healthy, but high-stakes rivalry continued into 2025, with Warholm and Dos Santos still among the leading names in any event. At the Stockholm Diamond League, Benjamin won in 46.54 seconds, Dos Santos finished second in 46.68, and Warholm placed third in 47.41. But the balance between Warholm and Dos Santos began to change in 2026.

Dos Santos started getting the better of his longtime rival more consistently, and their battles became increasingly one-sided. His two consecutive wins this week show that another record-breaking performance might not be as far away as once imagined.