Lionel Messi missed a penalty but Argentina still clinched top spot in Group C with a 2-0 win over Poland, who also squeezed into the last 16 on goal difference ahead of Mexico.
Mexico had beaten Saudi Arabia 2-1.
Argentina will face Australia in the Round of 16 while Poland will face France.
In other round 16 matches, England will face Senegal while Netherlands will battle the USA.
Brazil and Portugal have also qualified for the Round of 16.
