Thinking she had already won the gold medal, Elena Lashmanova came to almost a complete stop.
Inside the stadium with one lap to go in the women's 20-kilometer walk, Lashmanova briefly paused but soon got moving again and held on to first place to lead a Russian 1-2 on Tuesday at the world championships.
"The judges didn't really explain to us that we should do one lap before the home straight and finish, and that is why I stopped," said Lashmanova, the London Olympic champion and world record holder.
"But I quickly understood I should keep going."
The judges didn't really explain to us that we should do one lap before the home straight and finish, and that is why I stopped... But I quickly understood I should keep going
Lashmanova held off teammate Anisya Kirdyapkina with a final burst of speed to give Russia a sweep of the gold medals in the 20K events after Aleksandr Ivanov won the men's race.
After a dominating the walk through Moscow's morning heat, Lashmanova entered Luzhniki Stadium with a big lead but then stopped after crossing the line a first time.
With Kirdyapkina closing in fast, a judge urged the 21-year-old Lashmanova to get going again. She did, and managed to break the finishing tape on the second go around for gold.
Russians have won seven of the eight women's 20K walks since the event was added to the program at the 1999 worlds in Sevilla.
Russia even had eyes on a sweep Tuesday but Vera Sokolova was disqualified with about 500 meters to go, leaving Liu Hong of China to take bronze.
"It could have been the three of us on the podium,'' Lashmanova said.
Because of the walks, the host nation has moved up the medal standings into second place with five overall and two gold, right behind the United States with six overall and three gold.
Yelena Isinbayeva will try to add a third gold for Russia later Tuesday in the pole vault, even though the former world and Olympic champion has not come close to her best this season.
Also on the program on Day 4 of the championships is the women's heptathlon and 3,000 steeplechase, and the men's discus, 800 and 400.
Also, Mo Farah easily qualified for Friday's final of the 5,000 in front of a sparse crowd, coasting for the last half lap in the security he would finish in the top five.
"I just wanted to do as little work as possible, freshen my legs up and get through to the final," Farah said.
The heptathlon will go down to the last event with Ganna Melnichenko of Ukraine holding a 5,619-5,551 edge over Brianne Theisen Eaton, with the Canadian known as a better 800 runner.
It leaves newlyweds Theisen Eaton and decathlon world champion Ashton Eaton with the prospect of leaving Moscow with a gold each.