Mexico City, MX -
Despite ballots still being counted, Pena Nieto of the PRI (Institutional Revolutionary Party) is expected to win, having a 37% lead over his closest competitor so far, Andres Manuel Lopez Obrador, who has not conceded yet.
The official quick count, published by the electoral authorities (IFE), is based on returns from a sample of around 7,500 polling stations across Mexico and has a 0.5% margin of error.
During the vote, Mexican's were also electing a new congress and some state governors as thousands of police were out in full force trying to prevent drug cartel's from intimidating voters and to ensure safety during the elections.
Mr Pena Nieto declared: "We all won in this election. Mexico won."
"This is just the start of the work we have before us."
With his soap-actress wife Angelica Rivera by his side, he thanked Mexican voters for giving the PRI a second chance, saying his administration would have a "new way of governing".
The election campaign was dominated by the economy and the war on drugs.
"There will be no pact nor truce with organized crime," Mr Pena Nieto said.
He had been presented as the new face of the PRI, a break with the party's long and at times murky past that included links with drug gangs.
The party held on to power for 71 years until it was defeated in 2000.
Nieto has pledged to improve national infrastructure, provide more jobs with higher incomes and increase the quality of education in Mexico.