After solemnly closing the Holy Door, the Pope celebrated Mass in front of the basilica for a congregation of some 10,000 persons.
Only the Pope and his delegatees may celebrate mass at the high altar.
The Pope celebrated Mass before one million people in the Phoenix Park, Dublin.
The rain forced the Pope to celebrate Mass inside the basilica, as choirs chanted alleluias in celebration of the Resurrection.
The Pope is celebrating his victory over a rival.
Roman Catholic officials have said they expect 500,000 people at a 140-acre site to see the Pope celebrate the mass.
They had pistols that fire blanks and photographs of the square at the cathedral where the Pope celebrated Mass.
Tomorrow, when the Pope will celebrate Mass in Central Park, it is expected to be cooler and less muggy.
The Pope will celebrate a solemn Mass, during which hundreds of infants will be baptized.
The city authorities in Rheims had planned to spend $300,000 on an open-air Mass the Pope will celebrate there.