Winger Kamil Grosicki bagged a hat-trick for Poland in the first half of the match, and strikers Krzysztof Piątek and Arkadiusz Milik each added a goal in the second half.
Ilmari Niskanen scored the only goal for Finland in the 68th minute at Energa Stadium in the northern Polish city of Gdańsk.
The Polish side went into the match missing a number of key players, including midfielder Piotr Zieliński and defender Maciej Rybus, who have both tested positive for the coronavirus and were unavailable for duty.
Meanwhile, star striker Robert Lewandowski watched the game from the stands to save his strength ahead of upcoming Nations League matches.
Robert Lewandowski. Photo: PAP/Adam Warżawa
Poland are ranked 19th worldwide by football's governing body FIFA, while Finland are No. 56 in the FIFA table.
The Polish team is scheduled to play Italy in the group stage of the Nations League in Gdańsk on Sunday before taking on Bosnia-and-Herzegovina in the southwestern city of Wrocław on October 14.
(gs/pk)
Source: TVP Sport, PAP