The Olympic torch has been handed over to Chinese officials at a ceremony in Athens, amid scuffles between police and pro-Tibet demonstrators.
A small group of protesters tried to break through a police cordon to enter the stadium.
Thousands gathered as the flame was delivered and transferred to a lamp for its journey by plane to China.
The handover came as pro-Tibet protesters tried to storm the Chinese embassy in Nepal's capital, Kathmandu.
The torch's passage through Greece has been dogged by protests on human rights and Tibet.
The flame, which was lit in Olympia on 24 March, will be welcomed at a ceremony in Beijing's Tiananmen Square on Monday.
It will then tour 20 countries before returning for the opening on 8 August.
Sunday's formal handover was held in the Panathinaiko Stadium, where the first modern Olympics took place in 1896.
The route of the torch in Greece has been dogged by protests
The Chinese and Greek flags were marched in by Greek athletes to the strains of a band, before a circle of white-clad actresses dressed as ancient priestesses surrounded a podium as the torch was brought in.
Minos Kyriakou, president of the Hellenic Olympic Committee, passed the flame to chief Beijing organizer Liu Qi.
"The Olympic flame is the timeless symbol which stirs admiration, pride and faith [in] the Olympic ideals and values," said Mr Kyriakou.
"I hope the world community welcomes the flame and honours it".
Mr Liu pointed out that the summit of Mount Everest was on the torch's destination list, "testifying to the great strength of the Olympic movement in marking the progress of human civilisation".
The protesters tried to unfurl a banner which said "stop genocide in Tibet", but failed to enter the stadium or disrupt the solemn ceremony.
At least six people were arrested.
Police had warned they would confiscate all banners, signs or objects that might be thrown.
Greek organisers had altered the torch's route ahead of the ceremony to nullify protests. The torch has had a police guard and a group of runners to protect it.
Meanwhile, in Kathmandu, police baton-charged Tibetan exiles and Buddhist monks who were trying to storm an office of the Chinese embassy, and arrested at least 100 people.
The city is home to hundreds of Tibetan exiles, and the protest was the third over Tibet in the past week. Those detained in the previous incidents were released within hours.
Many arrested in Nepal were Buddhist monks or nuns
And in India's capital Delhi, exiled Tibetans launched an "independence torch" to tour the world in an anti-China protest.
The Tibetan alternative torch was unveiled in Delhi on Sunday and will next go to San Francisco on 9 April, when the Olympic torch is expected to arrive.
Tibet's government-in-exile, based in India, says about 140 people were killed in the crackdown on recent unrest by Chinese security forces. Beijing disputes this, saying 19 people were killed by rioters.
There has been little movement internationally towards a boycott of the Games, although French President Nicolas Sarkozy has said "all options are open" following the recent unrest in Tibet.
OLYMPIC TORCH ROUTE
Torch lit in Olympia on 24 March and taken on five-day relay around Greece to Athens
After handover ceremony, it is taken to Beijing on 31 March to begin a journey of 136,800 km (85,000 miles) around the world
Torch arrives in Macao on 3 May. After three-month relay all around China, it arrives in Beijing for opening ceremony on 8 August