Highlights from Rome where Dix and Powell were on form
Asafa Powell set the fastest time in the world this year with a storming run of 9.82 seconds to win the 100m at the Diamond League series in Rome.
The 27-year-old Jamaican beat his previous legal best this season of 9.83 to finish ahead of Frenchmen Christophe Lemaitre and Martial Mbandjock.
Britain's Mark Lewis-Francis finished a disappointing eighth in 10.30.
World bronze medallist Jenny Meadows was a creditable third in the women's 800m, clocking one minute 58.89.
Powell has lived in the shadow of his compatriot Usain Bolt in recent years, but the former world record holder has been the form sprinter so far this season.
DIAMOND LEAGUE 2010
12 June: New York, US
3 July: Eugene, US
8 July: Lausanne, Switzerland
10 July: Gateshead, UK
16 July: Paris, France
22 July: Monaco
6 August: Stockholm, Sweden
13/14 August: London, UK
19 August: Zürich, Switzerland
27 August: Brussels, Belgium
Powell ran 9.75 and 9.81 in Doha last month and 9.72 at last week's Bislett Games in Oslo (all wind-assisted) as well as 9.83 in Ostrava.
This was the fourth leg of the Diamond League Series but was classed as a non-scoring event.
Despite his improved time, Powell was unable to surpass the 9.77 that American Tyson Gay ran when beating him into second place last year, which still stands as the Olympic Stadium record.
Ironically, Powell was the second slowest of the nine runners out of the blocks, but by the halfway mark he was comfortably ahead.
"It was a pretty good race," he said. "The only problem was my start. My reaction was the worst of my entire life but I had a very good second part of the race.
"This year I changed a lot of things in my preparation. I've worked better, I've lost weight but I've gained power."
There was drama in the women's 100m, with world and Olympic champion Shelly-Ann Fraser and Mikkele Barber both disqualified for false starts.
Fraser did not bother to wait for the red flag that this season means instant disqualification at first offence, and walked off the track.
Barber's American team-mate Lashauntea Moore eventually claimed the honours in a time of 11.04 seconds.
Marlon Devonish, omitted from the British team for next weekend's European Team Championships, was sixth in the men's 200m in a time of 20.79 seconds as American Walter Dix won in 19.86.
There was more disappointment for Britain in the men's 400m as Michael Bingham finished fifth in 46.04, Jeremy Warner winning in 44.73, while in the 110m hurdles Will Sharman was last in 14.07 as Cuban Dayron Rubles triumphed in 13.14.
Chris Tomlinson was sixth in the men's long jump, recording 7.79 metres to comfortably trail American Dwight Phillips, who won easily following a leap of 8.42.
Meadows was narrowly edged out by Janeth Jepkosgei of Kenya (1:58.85) and Morocco's Halima Hachlaf, who won in 1:58.40.
Kate Dennison was seventh in the pole vault with an effort of 4.50 metres, Brazilian Fabiana Muhre winning with 4.70, and Goldie Sayers was also seventh in the javelin after a throw of 61.23m as Barbora Spotakova of the Czech Republic won with 68.66.