Krzysztof Piatek opened the scoring in the 35th minute after a cross from Tomasz Kedziora.
The hosts dominated the second half as they scored three more goals. Bayern Munich striker Robert Lewandowski converted a penalty in the 56th minute after Sheran Yeini touched the ball with his arm.
Kamil Grosicki made it 3-0 two minutes later after latching onto Piotr Zielinski's pass. Damian Kadzior scored his first international goal to complete the rout in the 84th minute.
Poland are on 12 points, five ahead of second-placed Israel. Third placed Austria are on six points.
The Austrians beat North Macedonia 4-1 for their second win of the qualifying campaign.
North Macedonia grabbed the lead after Austria's Martin Hinteregger scored an own goal. But a brace from Marko Arnautovic, a strike from Valentino Lazaro and an own goal from Egzon Bejtulai completed the 4-1 win for Austria.
Slovenia are fourth on five points after defeating Latvia 5-0 with Domen Crnigoj and Josip Ilicic both scoring twice and Miha Zajc sealing the result.
(Reporting by Anna Koper; Editing by Alan Charlish and Pritha Sarkar)
