It is a shame that fair play can be the deciding factor in such situations, it pushed Mexico to go all in and concede that late goal.
Otherwise Poland would still go through, but only because they received less yellow cards than Mexico.
I recall that happening only once, last WC when Japan qualified based on that criteria ahead of Senegal.
I agree,Argentina played with just football with one port and the only occasion Poland had was that header from the veteran player they had still playing in the national team,other than that they just totally parked the bus and this is a stupid thing to do against teams like Argentina.I think the hero of the game was their goalkeeper who gave them this truly undeserved qualification as Mexico showed much better game play and they scored the most magnificent goal so far of the whole tournament with that awesome free kick.
I wouldn't say it was undeserved for Poland to qualify for the next round simply because they didn't do well enough to posed just one goal threat against Argentina and it seemed they literally all out to only secure a draw, Mexico were not a different when they played Argentina as well, they literally just sat back too and tried to secure a draw which would have left Argentina in dire situation, I'd rather commend the Saudi Arabian team even though they lost the last two matches of the game, I'd say they were the only team of the other 3 besides Argentina to have a approached every game with the hope of getting something positive from it.
If the cases were reversed and it was Mexico playing Argentina last night, I strongly doubt they'd have done any better than Poland actually did, so If the game was unfair to any of the four teams, I'd say it was Saudi Arabia that got unlucky.
I agree about Saudi Arabia,their coach though which went viral with that motivation video after they were losing 1-0 to Argentina in the first game and after that speech they came in and overturn the situation in their favor 1-2,I must say their coach changed their mentality for the better.While they were always feeling inferior to any team they played in the World Cup they got and won against one of the strong contender for the title.I must say that the most unlucky game they had is exactly against Poland where they missed a penalty which could have changed the fate of that game.