A stunning election triumph by Mr Vicente Fox of the National Action Party (PAN) will give Mexico its first change of presidency in the 71 years it has been held by the Institutional Revolutionary Party (PRI).
The 58-year-old Mr Fox, who has led a trade mission to Ireland and has Irish ancestry, has promised a smooth take-over of power and to form a coalition government with former opponents.
Thousands of Fox supporters danced and sang in the streets of the capital as the early results showed a landslide victory.
Messages of congratulation for the president-elect, who will take office next December, poured in from around the world. But there was also praise for President Ernesto Zedillo whose electoral reforms helped ensure that Sunday's elections were the fairest in the country's history. Almost 10,000 foreign observers monitored the polling.
The Mexican stock markets rose sharply and the peso strengthened yesterday following the success of Mr Fox, who campaigned for more economic openness and closer relations with the US. President Clinton congratulated Mr Fox by telephone.
After a night of jubilant celebrations in the capital and around the country, Mexico must now adjust to the huge shift in the political landscape. The results were a rout for the PRI, which has also lost control of the senate and the governorship of Morales state.
Much attention will be paid to the reaction of the trade unions as they have been controlled in large part by the PRI, especially in the nationalised industries and the public sector.
Mr Fox not only won the presidency easily but his party will be the largest in the two houses of the Mexican Congress. The PAN fell short, however, by less than four per cent of winning an absolute majority in the Chamber of Deputies and the Senate.
With most of the presidential election results in, Mr Fox had won 43 per cent compared to 36 per cent for the PRI candidate, a former minister, Mr Francisco Labastida.
Trailing third was Mr Cuauhtemoc Cardenas of the leftwing Party of the Democratic Revolution (PRD) who won 16 per cent on his third run for the presidency. His party had the consolation of holding the powerful post of mayor of Mexico City won by Mr Lopez Obrador.
Mr Fox, who was once the head of Coca-Cola in Mexico, went out of his way to be conciliatory on election night after a bruising campaign in which he traded insults with Mr Labastida, even calling him a cross-dresser.
Mr Fox will now probably call on some members of Mr Labastida's party to "put together a transition government whose members are rigorously selected so that we have the best men", he said in an interview. A potential destabilising factor is a secret report on a list of persons who benefited from a massive bank bail-out in 1995 to save the country from bankruptcy.