Two World Records. Forty Minutes Apart.
Alison dos Santos crossed the line at the Letzigrund in Zurich on August 27, 2026, looked up at the clock, and saw 45.80. He had just become the second man in history to run the 400 metres hurdles under 46 seconds. Forty minutes later, Masai Russell came off the final hurdle in the women's 100 metres hurdles, also at the Letzigrund, and stopped the clock at 12.09. The first woman under 12.10. In one evening, at one stadium, the sport rewrote two record books that had stood for years.
45.80: The Number That Buried Five Years of History
Dos Santos, 26, from Brazil, entered Zurich having run 46.43 at the Silesia Diamond League four days earlier, a world lead he described as "the sign." He drew lane six, with Warholm in lane seven immediately outside him. By the fourth hurdle, halfway down the backstretch, dos Santos had already closed down the stagger on the Norwegian, famous for his blistering early pace. Coming off the final bend, he had a commanding lead. The clock stopped at 45.80. Karsten Warholm's record of 45.94, set winning Olympic gold at Tokyo in 2021, a race in which dos Santos had taken bronze in 46.72, was gone by 0.14 seconds. Dos Santos improved his own personal best by 0.49 seconds in a single race. Warholm finished second in 46.69, five years after he became the first man to break 46.
"I have no words to explain what happened other than: I just broke the world record.
"Alison dos Santos after the race
Warholm: "It Is a New Level"
The previous record holder was in lane seven, watching dos Santos pull away. Three times world champion, Warholm had held the mark since Tokyo 2021 and knew precisely what it meant to be the first man under 46. His reaction after the race was unguarded. He acknowledged the sting, and he named what he saw.
"I would be lying if I said it doesn't bother me a little. It's a record that's been part of me for five years. But when he brings out 45.8, it's a new level.
"Karsten Warholm on the new world record
12.09: The First Woman Under 12.10
Less than forty minutes after dos Santos celebrated, Russell stood in the blocks. The 26-year-old from Washington, D.C. had spent 2026 running the second and third fastest legal times in history behind Tobi Amusan's 12.12, set in Eugene at the 2022 World Championships. In Zurich, with no wind at all (the official reading was 0.0), she ran 12.09. Amusan, the dethroned record holder, finished second in 12.23, a season's best. It was Russell's eleventh consecutive victory in the event this year. The wind reading matters here: Russell noted afterwards that a legal tailwind of 1.9 metres per second "could have been a sub-12 race." She is now the first woman to simultaneously hold the world record and the Olympic title in the event since Bulgaria's Yordanka Donkova won gold in Seoul in 1988.
"I've been chasing it and the world's been talking about it. Just to finally do it, it's like: all right, I can breathe a little bit. Not all the way, but partially.
"Masai Russell on breaking the world record
Dos Santos, 400m hurdles WR
45.80 (Zurich, August 27 2026)
Previous record: Warholm, Tokyo 2021
45.94 (margin: 0.14 sec)
Dos Santos previous personal best
46.29 (improved by 0.49 sec)
Russell, 100m hurdles WR
12.09 (Zurich, August 27 2026)
Previous record: Amusan, Eugene 2022
12.12 (margin: 0.03 sec)
Wind reading for Russell's race
0.0 m/s (dead calm)
Letzigrund world records hosted
29 (first since 2009 before Thursday)
Russell's 2026 win streak
11 consecutive 100m hurdles races
What Comes Next: Brussels and Beyond
Both records are subject to World Athletics' usual ratification process. The Wanda Diamond League Final takes place in Brussels one week after Zurich. The World Athletics Ultimate Championship follows. Russell has said she does not know her own ceiling and has not ruled out breaking 12 seconds. Dos Santos has now beaten Warholm in the Diamond League five consecutive times in 2026. The Tokyo rivalry has a new chapter, with Dos Santos on the right side of the record books this time, and the race for the Diamond League title still live. The Letzigrund has now hosted 29 world records across its history. Thursday's double was the first since 2009. It may be a long time before any athletics venue matches an evening like this one.