Portugal dominated with close to 70% possession against Uruguay in the first half of their World Cup Group H match on Monday but it was the South Americans who came closest to scoring in the encounter that remained goalless at halftime.
Rodrigo Bentancur charged through but saw his 32nd minute shot blocked by keeper Diogo Costa.
Portugal, who will become the third team after France and Brazil to qualify for the last 16 with a win, lacked the final pass despite the presence of Cristiano Ronaldo, Joao Felix and Bruno Fernandes.