Sunday was a historic day in Mexico. Elections across 12 states produced victories for the center-right National Action Party - and toppled the ruling party. CCTV's correspondent reports from the embattled northeastern Mexican state of Tamaulipas, where violent crime is rampant.

Brave citizens witness another gun fight in the Mexican state of Tamaulipas. With the Gulf and Zetas cartels battling for power, it's among the most unsafe places in the world.

But history was made in Sunday's election, when Francisco Cabeza de Vaca beat the candidate of the Institutional Revolutionary Party, PRI, toppling that party from power for the first time in nearly nine decades.

"Ladies and Gentlemen, we are just hours away from ending the 86-year rule of bad governments. We are making history. The winds of change are blowing. And it's time for the old party to go," said Francisco Cabeza De Vaca, Tamaulipas Governor-Elect.

The PRI also lost in the crucial Gulf coast state of Veracruz, which has five million registered voters.

But it is Tamaulipas that has captured international attention lately, especially following the recent kidnapping and escape of football star Alan Pulido. Tamaulipas has one of the highest kidnapping rates in the world.

And two former state governors, Tomas Yarrington and Eugenio Hernandez, both of the ruling PRI, stand accused in the United States of having ties with organized crime.

In his new book, investigative journalist Humberto Padgett documents the connection between Tamaulipas politicians and criminal groups. Padgett says the winner of Sunday's election now has a historic opportunity to end corruption there.

"Cabeza de Vaca would criminally prosecute his predecessors in order to distinguish his administration from others that corrupted Tamaulipas to the extent that is one of the most violent places in the world," said Humberto Padgett, author of "Tamaulipas Narco Governors".

Foreign investors - especially those in the energy sector -- are keeping a close eye on Tamaulipas and Veracruz.

Political observers say the losses the PRI suffered in Sunday's election will weaken Mexico's ruling party heading toward the 2018 presidential election.