Hugo Chavez's ruling Socialist Party has won nearly all of Venezuela's 23 states in elections, while Henrique Capriles, who lost to Chavez in October's presidential vote, consolidated his position as top opposition leader by winning re-election as governor.
Capriles, the 40-year-old governor of Miranda, beat Chavez's former vice president Elias Jaua in elections on Sunday, and retained control of the country's second-most populous state.
The ruling party, however, extended its control over the South American OPEC nation, snatching four states from the opposition to win 20 of the 23 states.
Possibly benefiting from a wave of sympathy over Chavez's battle to recover from cancer surgery, it staged several upsets, including a victory in the most populous state of Zulia.
The youthful Capriles' re-election will help maintain unity among the opposition in a potential election against Vice President Nicolas Maduro, Chavez's anointed successor.
"I'm happy for Miranda, but not for our Venezuela," Capriles said, accusing Socialist Party candidates of bolstering their showing by offering handouts to voters and exploiting Chavez's illness.
"The day must come when we defeat this abuse of power."
He won by just four percentage points, lower than his camp and most analysts had predicted.
Another prominent opposition leader, Henri Falcon, a former government ally who broke with Chavez in 2010, also won re-election.
His broad popularity and appeal to working class voters have left many considering him a potential challenger to the socialist government.
"Nobody here is surrendering," said Ramon Guillermo Aveledo, head of the opposition Democratic Unity coalition.
In southern Bolivar state, the opposition candidate refused to accept the official results that showed him losing on Sunday.
He alleged irregularities in the vote count and called on supporters to protest in the street.
The results signaled the continued dominance of Chavez's socialist leadership despite his ill health.
The vote date may have hurt the opposition, with plenty of middle-class opposition supporters already starting holidays.
Chavez's brother Adan comfortably held their agricultural home state of Barinas, while the president's former military comrade Francisco Arias unseated a prominent opposition leader, Pablo Perez, in oil-rich Zulia state.
Turnout was a poor 54 per cent, reflecting weariness with politics after the recent presidential campaign and the closeness of Christmas.
The nation remains focused on Chavez's recovery in Cuba from Tuesday's six-hour operation - his fourth since he was diagnosed with cancer in the pelvic region in mid-2011.
Officials say Chavez has regained full consciousness, is giving instructions from his bed, and was following Sunday's vote closely.
"The commander-president continues to stabilize. The trend remains positive," his son-in-law Jorge Arreaza, who serves as science and technology minister, said from Havana.
The official updates of his health are shy on details, however, so speculation is rife that Chavez may be in a life-threatening situation in Havana's Cimeq hospital with both a difficult post-operative recovery and a possible spreading of the cancer.
Chavez, 58, is due to start a new term on January 10, but has named Maduro as his preferred successor should he be incapacitated.
That would trigger a new presidential poll within 30 days.