Mexico's old guard sailed back into power after a 12-year hiatus Sunday as the official preliminary vote count handed a victory to Enrique Pena Nieto, whose party was long accused of ruling the country through corruption and patronage.

The second place candidate, leftist Andres Manuel Lopez Obrador, refused to concede, saying he would wait for a full count.

The Federal Electoral Institute's representative count said Pena Nieto of the Institutional Revolutionary Party, or PRI, won about 38 percent of the vote, prompting wild cheers from a party that was voted out in 2000 after 71 autocratic years in power.