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.
Rodridgo 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.
Pepe becomes third oldest World Cup outfield player
Centre-back Pepe will become the third oldest outfield player in World Cup history after he was picked to start for Portugal against Uruguay on Monday.
The 39-year-old comes in for the injured Danilo, who mysteriously suffered broken ribs, as one of three changes made by Portugal coach Fernando Santos.
Nuno Mendes gets the nod over Raphael Guerreiro at left-back for Portugal and William Carvalho comes into midfield in place of Otavio.
Edinson Cavani was picked ahead of fellow Uruguay icon Luis Suarez in attack as coach Diego Alonso switches his formation from a back four to a back three.
Centre-back Sebastian Coates comes in with winger Facundo Pellistri dropping to the bench while Guillermo Varela is picked at right wing-back instead of veteran Martin Caceres.
Diogo Costa; Joao Cancelo, Ruben Dias, Pepe, Nuno Mendes; William Carvalho, Ruben Neves; Bruno Fernandes, Bernardo Silva, Joao Felix; Cristiano Ronaldo (capt)
Coach: Fernando Santos (POR)
Sergio Rochet; Jose Maria Gimenez, Diego Godin (capt), Sebastian Coates; Guillermo Varela, Federico Valverde, Rodrigo Bentancur, Matias Vecino Mathias Olivera; Edinson Cavani, Darwin Nunez
Coach: Diego Alonso (URU)