In the southern state of Oaxaca, PRI gubernatorial contender Ulises Ruiz claimed victory over Gabio Cue, an opposition coalition candidate who had the backing of President Vicente Fox's conservative National Action Party and the leftist Party of the Democratic Revolution. Oaxaca has been a PRI stronghold in its 71-year rule over Mexico and Cue said he would challenge the result, claiming the vote was rigged.
In the border town of Tijuana, gambling tycoon Jorge Hank Rhon of the PRI had a narrow 1 percentage point lead over Jorge Ramos of Fox's National Action Party, or PAN, in the race for mayor. Ramos also planned an appeal.
The two wins may improve presidential chances in 2006 for the PRI, which ruled Mexico's presidency for 71 years until Fox's upset in 2000.