By Anthony Boadle
BRASILIA (Reuters) - Brazil's heated presidential race has tightened ahead of a Sunday vote, several opinion surveys showed on Saturday, with right-wing President Jair Bolsonaro eroding a slight advantage for leftist challenger Luiz Inacio Lula da Silva in most polls.
Surveys by pollsters Datafolha and Quaest both showed Lula with 52% of valid votes against 48% for Bolsonaro, down from a 6 percentage-point lead three days prior, putting the incumbent in striking distance of a come-from-behind victory.
A survey by pollster MDA showed Lula's edge slipping to just 2 percentage points, equal to the margin of error for the poll commissioned by transport sector lobby CNT.
Most polls still suggest Lula is the slight favorite to come back for a third term, capping a remarkable political rebound after his jailing on graft convictions that were overturned. But Bolsonaro outperformed opinion polls in the first-round vote on Oct. 2, and many analysts say the election could go either way.
The final opinion surveys by pollsters IPEC and AtlasIntel, however, showed Lula holding a stable and slightly larger lead.
IPEC showed the leftist ahead by 54% to 46% of valid votes, excluding undecided voters and those planning to spoil their ballots. AtlasIntel, among the most accurate pollsters in the first round, showed Lula's lead holding at 7 percentage points.
Bolsonaro wrapped up his campaign in the key state of Minas Gerais, leading a motorbike rally with supporters. Lula walked with thousands of backers on one of Sao Paulo's main avenues after telling foreign reporters his rival was not fit to govern.
The deeply polarizing figures also attacked each other's character and record in their final televised debate on Friday night. Bolsonaro opened the debate by denying reports he might unpeg the minimum wage from inflation, announcing instead he would raise it to 1,400 reais ($260) a month if re-elected, a move that is not in his government's 2023 budget.
With their campaigns focusing on swaying crucial undecided votes, analysts said the president gained little ground in the debate to win a race that polls had shown roughly stable since Lula led the first-round voting by 5 percentage points.
That result was better for Bolsonaro than most polls had shown, giving him a boost of momentum to start the month, but the past two weeks of the campaign have presented headwinds.
A week ago, one of Bolsonaro's allies opened fire on federal police officers coming to arrest him.
On Sunday, one of his closest associates, Congresswoman Carla Zambelli, chased a Lula supporter into a Sao Paulo restaurant at gun point after a political argument in the street, videos on social media showed. Zambelli told reporters she knowingly defied an electoral law that bans the carrying of firearms 24 hours before an election.
In their first head-to-head debate this month, Lula blasted Bolsonaro's handling of a pandemic in which nearly 700,000 Brazilians have died, while Bolsonaro focused on the graft scandals that tarnished the reputation of Lula's Workers Party.
On Friday night, both candidates returned repeatedly to Lula's two terms as president from 2003 to 2010, when high commodity prices helped to boost the economy and combat poverty. Lula vowed to revive those boom times, while Bolsonaro suggested current social programs are more effective.
(Reporting by Ricardo Brito and Anthony Boadle in Brasilia, Gabriel Stargardter in Rio de Janeiro and Brian Ellsworth in Sao Paulo; Editing by Brad Haynes, Chris Reese and Daniel Wallis)