Piqued by suggestions of a possible decline, Usain Bolt responded with a blistering season debut at 200 meters and a new track record at the Bislett Games on Thursday.
"I'm not in as bad shape as I thought I was," Bolt said after his emphatic victory.
Bolt, whose condition was questioned after losing the 100 meters by one hundredth of a second in Rome the week before, finished in 19.79 seconds. He is the only one to break 20 seconds this season.
"Overall it was a good run, I can't complain. It's sub 20," said the Jamaican, who holds the world record at the distance in 19.19. "I could have done better. I think I need to work on my corners but otherwise it was a good race."
Bolt topped the Bislett record set by Frank Fredericks of Namibia in 1996 by three hundredths of a second.
"At the end of the day it's not about time. It's about winning. Because if I run 20 flat at the world championships and I win, I'll be happy," Bolt said.
After losing to Justin Gatlin of the US in Rome, Bolt was unfazed by a false start by European 200 champion Churandy Martina of the Netherlands. Martina was disqualified and Bolt powered on, finishing strongly in lane six and leaving the crowd on its feet.
"It's always good to have someone directly in front of you," said Bolt of Martina, who had been in lane seven. "It helps to push you harder to get past them on the corner. But you have to learn. This is always good, a learning curve. If it happens in the world championships, then it's already happened here so you know how to deal with it."
Bolt was disqualified for a false start at the 2011 world championships in South Korea.
"I know how it feels, it's not a good feeling," he laughed.
"Now back to Jamaica to prepare for the worlds (in August). My goals remain the same, to be the best in the world and to win three gold medals in Moscow."
Earlier, Olympic champion Meseret Defar of Ethiopia delighted the crowd by running the women's 5,000 in a world-leading 14:26.90 - just 15.75 seconds off her great rival Tirunesh Dibaba's world record.
"I felt very comfortable throughout the race. I knew I have the shape. I think I'm in world record shape, but wasn't confident to try it," Defar said.
Russia's Yelena Sokolova caused a brief moment of panic in the race when she inadvertently walked back in the runners' path after her long jump. She had to jump again, to get out of their way, much to the amusement of the crowd at the 15,400 Bislett Stadium.
There was a surprise in the high jump, where Russia's Olympic bronze medalist Svetlana Shkolina leapt 1.97 meters to beat Olympic and world champion Anna Chicherova into third. Emma Green-Tregaro of Sweden was second.
Blanka Vlasic could only tie for fifth as she makes her return from a long-standing Achilles injury.
"Not my day. When the competition started I was totally empty emotionally. I can't explain it but the feeling was strange. I couldn't push," the Croatian said. "Maybe it's natural after a long break and a lot of problems."
Tiffany Porter of Britain won the women's 100 hurdles in 12.76, and Czech hurdler Zuzana Hejnova of the Czech Republic continued her great form with a season's best of 53.60 to take the 400 hurdles.
Ekaterina Poistogova of Russia emerged victorious in the women's 800, and Ivet Lalova of Bulgaria edged Murielle Ahoure of Ivory Coast by one hundredth of a second to win the 100 meters in 11.04 seconds. Both clocked season's bests.
"Before the race everything went wrong," said Lalova, whose flight was canceled and hotel arrival delayed to the early hours. "But sometimes everything is wrong at the beginning and great at the end."
The 19-year-old Conseslus Kipruto led a Kenyan sweep of the top six places in the men's 3,000 steeplechase, winning in 8:04.48 ahead of Ezekiel Kemboi and Hillary Kipsang Yego.
Yousef Ahmed Masrahi of Saudi Arabia finished strongly to win the men's 400, and Djibouti's Ayanleh Souleiman won the mile in 45.33, followed by Ramon Miller of the Bahamas with a season best 45.58. Nigel Levine of Britain was third in 45.63.
Djibouti's Ayanleh Souleiman won the Dream Mile in 3:50.53. Nixon Kiplimo-Chepseba of Kenya ran a personal best 3:50.95 to claim second.