BBC: Venezuelan President Hugo Chavez has narrowly lost a referendum on controversial constitutional changes.
Voters rejected the raft of reforms by a margin of 51% to 49%, the chief of the National Electoral Council said.
Mr Chavez described the defeat as a "photo finish", and urged followers not to turn it into a point of conflict.
Correspondents say the opposition could barely hide their delight and that the victory will put a brake on Mr Chavez's self-styled "Socialist revolution".
Celebrations by the opposition began almost immediately in the capital, Caracas, with activists cheering, beeping car horns and waving flags.
"Venezuela won today, democracy won today, and I am sure that this victory for the Venezuelan people will have a very important impact in the rest of Latin America," Leopoldo Lopez, opposition mayor of Caracas' Chaqua municipality, told the BBC. Chavez defeated over reform vote >>>
Mark Alexander
