Captain Robert Lewandowski ended Poland's scoring drought as he and Kamil Grosicki struck in the first half to give Adam Nawalka's team a 2-0 lead.
Bayern Munich striker Lewandowski's fine header opened the scoring in the 32nd minute and Grosicki doubled the home side's lead with a cool finish just before the interval.
Lewandowski's 52nd international goal was Poland's first since last October as they failed to score in friendly games against Uruguay, Mexico and Nigeria since.
South Korea fought back, though, and scored twice within two minutes through Lee Chang-min and Hwang Hee-chan, with the Polish defence slow to react. However, Zielinski had the final say and won the match with an expertly curled 22-metre shot.
Poland face Colombia, Japan and Senegal in Group H of the World Cup in Russia. South Korea, who have qualified for a ninth successive World Cup finals, have been drawn with defending champions Germany, Mexico and Sweden in Group F.
(Reporting by Angel Krasimirov)
