By Mike Rowbottom

Ashton Eaton, pictured winning world indoor gold this year, became the first decathlete to win an event at a Diamond League meeting in Oslo as he earned victory in the 400m hurdles  ©AFP/Getty ImagesAshton Eaton became the first victorious decathlete at an Diamond League meeting tonight as he earned victory in the 400 metres hurdles at the fifth of the International Association of Athletics Federation's (IAAF) 14 circuit events at the Bislett Stadium in Oslo -  where United States team-mate Allyson Felix won the 200m on her debut in the Norwegian capital.

Eaton, world and Olympic champion in his 10-event speciality, has been concentrating on the hurdles in a season without a major decathlon title to contest, and defeated a field which included South Africa's world bronze medallist LJ Van Zyl and Britain's European champion Rhys Williams in 49.16sec, although the race was not one of the scoring events on the night for this year's Diamond League.

He is the tenth fastest 400m hurdles man this year and said he would like to break 49 seconds in his next meeting at Ostrava on Tuesday (June 17).

Felix earned her first big win since pulling her hamstring in last year's World Championship 200m final as she clocked 22.73 to defeat a field which included the world 100 and 200m silver medallist Murielle Ahoure of the Ivory Coast.

The 28-year-old US sprinter, three times a world champion and reigning Olympic champion at 200m, recorded 22.44 in finishing third at the Eugene Diamond League meeting last month, and is clearly on her way back to top form after what she has described as a "rocky road" back to fitness.

Ahoure could only manage fourth place in 22.99 behind France's Myriam Soumare, who clocked 22.98, and Britain's 20-year-old former world junior 100m champion Jodie Williams, second in 22.97.

Olympic 200m champion Allyson Felix falls to the track during last year's World Championship 200m final in Moscow with a pulled hamstring. She has had a 'rocky road' to recovry, but tonight won her first Diamond League meeting of the season in her debut at Oslo's Bislett Stadium ©AFP/Getty ImagesOlympic 200m champion Allyson Felix falls to the track during last year's World Championship 200m final in Moscow with a pulled hamstring ©AFP/Getty Images

Felix's US compatriot Tianna Bartoletta produced one of the other outstanding performances of the evening with a winning long jump of 7.02 metres, the best seen in the world so far this year.

Jamaica's Novlene Williams-Mills, a breast cancer survivor, won the women's 400m in 50.06, ahead of US athlete Natasha Hastings, who clocked 50.60, and Botswana's 2011 world champion Amantle Montsho, who was timed at 51.05.

Kenya's world 800m champion Eunice Sum won in 1min 59.02 ahead of US world bronze medallist Brenda Martinez in 1:59.68 in a race where the 2009 world champion, South Africa's Caster Semenya, was 12th and last in 2:03.68.

Pascal Martinot-Lagarde of France took the 110m hurdles in 13.12, the fastest time in the world this year.

He finished 0.24sec clear of a field that included silver and bronze medallists at the most recent Olympics and World Championships.

World pole vault record holder Renaud Lavillenie, a late addition to the Oslo field, produced an expected victory.

The French athlete, who bettered Sergey Bubka's 1993 mark of 6.15m when he cleared 6.16m in February, only needed to vault 5.77m to finish clear of his nearest challenger, Germany's Malte Mohr, who managed 5.70m.

Sandra Perkovic of Croatia, who won the Diamond Race with seven wins out of seven in the discus last year, maintained her perfect record Diamond League with her third consecutive win this season, recording a best of 67.17m.

Ayanleh Souleiman of Djibouti, the world indoor 1500 champion, won the ExxonMobil Dream Mile in 3:49.49 ahead of New Zealand's Nick Willis, who clocked a personal best of 3:49.83.

In the 5,000m, Yenew Alamirew of Ethiopia produced the fastest time recorded so far this season, 13:01.57, to finish ahead of Kenya's Caleb Ndiku and Galen Rupp of the United States, who clocked 13:02.15 and a season's best of 13:03.35 respectively.

The Diamond League moves to New York for the Adidas Grand Prix on Saturday (June 14).

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