Sonia O'Sullivan lost touch with pack before the 3,000m mark

Sonia O'Sullivan made a tearful departure from the Stade de France after finishing a distant last in the 5,000m at the World Championships.

The Irish runner never looked comfortable in a race which could prove her final appearance at the World Championships.

O'Sullivan was a pale shadow of the athlete who triumphed over the distance at the World Championships in Gothenburg.

The Olympic silver medallist went into the race with high hopes after showing improved form in the fortnight prior to the championship.

However, she failed to cope with a relatively modest injection of pace midway through Saturday's final and eventually came home in 15:36.62 - almost 45 seconds behind the surprise winner Tirunesh Dibaba.

The 33-year-old missed around four months training in the early part of this year with an Achilles injury.

She struggled badly in a number of races on the European circuit in the early part of the summer but then looked rejuvenated when she ran well in Zurich a week before the Championships.

However it will went horribly wrong on Saturday evening and there will now be major doubts whether she will be a genuine contender for next year's Olympics.

O'Sullivan has spoken of many occasions of her intention to compete in Athens and she indicated in a BBC interview last week, that she might consider prolonging her career for several years after that.

Dibaba was this year's world junior cross country champion

Ethiopia's Dibaba produced a brilliant sprint finish to claim the gold medal.

Her compatriot Berhane Adere had been fancied to take the title after winning the 10,000m but it was Dibaba who edged out European champion Marta Dominguez and Kenya's Edith Masai to win the gold.

Dibaba, who triumphed in this year's World Junior Cross Country Championship, won in 14:51.72 with Dominguez clocking 14:52.26 and Masai (14:52.30) pipping Russia's Yelena Zadorozhnaya for the bronze medal in a desperately tight finish.

Adere, who had been in contention at the bell, faded in the closing 200m to finish in 10th place - just ahead of Sydney Olympic champion Gabriela Szabo.

Dibaba is the youngest ever gold medallist at a World Championships.

She beats the record of Irina Stankina who won the 20km Walk in 1995.

Ireland's last hopefuls of the games, the men's 4x400m relay squad produced a season's best of 3:04.31 but it wasn't enough to earn a place in Sunday's final.

Belfast runner Paul McKee and David McCarthy ran especially storming legs while Gary Ryan and David Gillick also performed creditably.