An opposition party that ruled Mexico for over 70 years has claimed victory in elections for the governor of the country's most populous state.
Enrique Pena is a youthful face for the party of Mexico's past
With almost all the ballots counted, results show the Institutional Revolutionary Party, or PRI, has won 47% of the vote in the state of Mexico.
The party's candidate, Enrique Pena, said it was a "strong and clear victory".
The PRI hopes to win back the presidency in an election next year.
The party ruled Mexico for 71 years during the 20th century, and was tarnished by years corruption and repression.
Victory for the PRI is regarded as a blow to President Vicente Fox, whose election in 2000 was seen as a political watershed for the country.
Mr Pena, at just 38, is not widely associated with the worst excesses of the PRI's days in power.
Victory in the state is expected to give the PRI a foothold in Mexico's most populous region, one that encompasses affluent suburbs surrounding Mexico City, as well as areas of poverty, indigenous villages and the state capital, Toluca.
Indigenous people in areas around Mexico City also voted
The left-leaning candidate Yeidckol Polevnsky, whose Party of the Democratic Revolution (PRD) hopes to win the presidency for the mayor of Mexico City, trailed in third with 24% of the votes counted so far.
Mexican newspaper El Universal said the mayor, Andres Manuel Lopez Obrador, who has campaigned for Ms Polevnsky, must share in her defeat.
Results showed Mr Fox's conservative National Action Party was in second place behind the PRI, having won 24.8% of the vote.
The PRI was also expected to regain control of the western state of Nayarit, which it lost in a 1999 vote.