The Digis poll commissioned by news channel SkyTG24 showed Giuliano Pisapia garnering 53.5 percent of voter intentions in Milan -- Italy's economic capital and Berlusconi's home town -- against Letizia Moratti with 46.5 percent.
In Naples, Luigi De Magistris was ahead of his rival Gianni Lettieri with 54.5 percent against 45.5 percent.
The polls surveyed voters just before the elections, and released immediately after polling ended at 3:00 pm today.
Official preliminary results were to be released later on today.
Italians had voted in a second round of partial local elections on Sunday and Monday that is being seen by some commentators as a bellwether for the fate of Berlusconi's government and even of his political future.