Duda, a conservative who is bidding for a second term in office, won 41.8 percent of the vote, the poll showed.
His main opposition rival, Rafał Trzaskowski, the mayor of Warsaw, won 30.4 percent, according to exit poll results released seconds after voting ended at 9 pm.
Turnout was a record 62.9 percent, broadcaster TVP Info reported.
The official results are expected to be announced over the next few days.
(pk/gs)
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