Britain's Princess Beatrice (front 2nd L) competes in the Olympic Park Run in Stratford, east London, March 31, 2012. [Photo/Agencies]

LONDON - The first public event at London's Olympic Stadium has allowed 5,000 runners to cross the finish line on the track for this year's Summer Games.

The winners of a nationwide ballot ran a 5-mile (8-kilometer) route around the Olympic Park that ended in the 80,000-seat stadium where the likes of Usain Bolt will compete for gold in less than five months.

Britain's Princess Beatrice crosses the finish line at the Olympic Park Run in Stratford, east London, March 31, 2012. [Photo/Agencies]

Queen Elizabeth II's granddaughter, Princess Beatrice, took part and presented the fastest finishers medals.

The first member of Britain's royal family to complete the London Marathon, Princess Beatrice says she was "thrilled to be able to play my part in such an historic occasion."

The first person to officially cross the finish line was wheelchair-bound spina bifida sufferer Stuart Bloor.

Britain's Princess Beatrice poses for photographs after finishing the Olympic Park Run in Stratford, east London, March 31, 2012. [Photo/Agencies]