Raggi congratulates Gualtieri who is on track to be the next mayor of Rome.
Centre-left candidates look set to win run-off mayoral elections in Rome and Turin, based on exit polls after voting stopped on Monday afternoon.
The Opinio exit poll for state broadcaster RAI gave Rome's centre-left Partito Democratico (PD) candidate Roberto Gualtieri 59-63 per cent of the vote, against 37-41 per cent for his centre-right rival Enrico Michetti.
The result is not yet official but Gualtieri - a former economy minister - is already speaking as the mayor of Rome. He thanked his opponents in the race and pledged to be a "mayor for all Romans."
Gualtieri was backed in the run-off by Carlo Calenda, the liberal-centrist Azione leader who came third in the Rome mayoral race, with support also from Giuseppe Conte, the former prime minister and leader of the populist Movimento 5 Stelle (M5S).
Michetti, a lawyer and radio host, was put forward by the centrodestra alliance made up of the far-right Fratelli d'Italia (FdI) of Giorgia Meloni; the right-wing Lega of Matteo Salvini; and the centre-right Forza Italia of Silvio Berlusconi.
In the first round earlier this month Michetti took the lead in the polls - without reaching the 50 per cent plus one required to win outright - however last week his campaign took a knock after he was forced to apologise over accusations of anti-Semitism.
The capital's outgoing M5S mayor Virginia Raggi, who failed to make the run-off, could have supported Gualtieri or Michetti but chose not to endorse either candidate.
On Monday afternoon she congratulated Gualtieri and said it was "an honour to be at the helm of this wonderful city" for the last five years.
Meanwhile in Turin the centre-left Stefano Lo Russo (PD) looks set to beat the centre-right Paolo Damilano to succeed mayor Chiara Appendino of the M5S.
Mayoral run-offs were held in 65 towns and cities in Italy over the last two days but all eyes were on Rome and Turin where the apparent PD victories are set to follow centre-left wins in Milan, Naples and Bologna two weeks ago.
The official election results are due to be announced this evening. Photo Leggo.
— Nicola Zingaretti (@nzingaretti) October 18, 2021