Justin Gatlin sped through the rain on Thursday to complete the men's 100-200 double on a night of triumph for the United States at the 10th world championships.
Americans won three of the five titles at stake on the sixth day and U.S. sprinters took the first four places in the 200 metres.
Olympic 100 champion Gatlin confirmed the impression that he is in a class of his own in Helsinki by winning in 20.04 seconds before a sell-out crowd on another cold, wet and generally miserable night at the Olympic stadium.
"I consider myself right now the king of sprints," Gatlin said. "When I came off the turn I was going to gun it, that's what I did then I had to have enough in the tank at the end.
"I had to make sure I was calm, patient and made my way strong throughout the race."
Gatlin led off the bend and had the race won in the straight, glancing to his left to confirm he had defeated team mate Wallace Spearmon.
Spearmon, selected for the U.S. team when Olympic champion Shawn Crawford withdrew with a foot injury, was second in 20.20. John Capel, who had an automatic place in the championships as defending champion, was third in 20.31 just ahead of Tyson Gay.
THREE TITLES
Three titles were decided in the space of a minute in the field events.
American Walter Davis recorded his winning leap in the men's triple jump, Franka Dietzsch of Germany took the title-deciding lead in the women's discus and Dutchman Rens Blom clinched the men's pole vault.
Michelle Perry won the 100 metres hurdles for the United States after her team mate and Olympic champion Joanna Hayes crashed into the penultimate flight.
Blom overcame cramps in his legs and an indifferent start to give the Netherlands their first pole vault title at either a world championships or Olympic Games.
He cleared 5.80 metres on an awkward evening for vaulting to relegate favourite Brad Walker of the United States into second place.
"I've been waiting to jump this well," said Blom. "This really was my day. The world championships has given me wings."
Perry, who has converted from the heptathlon to the hurdles this season, clocked 12.66 to take gold ahead of Jamaicans Delloreen Ennis-London and Brigitte Foster-Hylton.
"I was able to run without hitting any of the hurdles," she said. "During the race I didn't even notice what happened to Joanna."
Davis, a former basketball player, took advantage of the absence of injured defending champion Christian Olsson to record the biggest victory of his career.
"I was trying to catch a wind. I caught a nice wind and I hit a big one," he said.
"After my big jump I started looking at my watch, because I was telling myself this is my year, this is my time to win."