Slovakia with their fourth win in five against Poland, this time 2-1 in Group E, was fully deserved against opponents who ended the game with ten men.
After a lively start from both teams Poland gradually gained the upper hand only to fall behind thanks to the brilliance of Mak.
The Slovakian nut megged his marker and whilst keeper Szczesny perhaps should have done better the ball hit the post and rebounded into goal off the former Arsenal stopper.
Lewandowski was the main threat for Poland but the Slovakian underdogs although conceding possession to their opponents always looked dangerous on the break and resolute in defence.
The Poles dominated the early period of the second period helped by levelling the score immediately after the break through Linetty but this was quickly undermined in the 62nd minute as Krychowiak was shown red for a second yellow card offence.
Slovakia took advantage of their numerical advantage within 7 minutes as Inter Milan defender Skriniar reacted quickest at a corner to turn and fire home.
The Polish defence had struggled throughout and despite a spirited late rally Slovakia comfortable held out.
EURO 2020 - GROUP STAGE
Poland: 1 (Linetty 46)
Slovakia: 2 (Szczesny 18og, Skriniar 69)
Venue: Saint Petersburg Stadium, St Petersburg
Man of the Match: Skriniar (Slovakia)