Portugal cemented top spot in Group 2 with a 2-0 win over the Czech Republic on Thursday evening.
Fresh from the win over Switzerland, Selecao went with Gonçalo Guedes in place of Otavio while Diogo Costa replaced Rui Patricio in goals.
The home side got the opening goal in the 33rd minute courtesy of a fine finish from Joao Cancelo, before Guedes doubled the lead five minutes later.
Spain secured their first win of the campaign after edging past Switzerland 1-0 on Thursday night.
La Roja coach Luis Enrique made nine changes from the draw against the Czech Republic, with only Gavi and Unai Simon retaining their spots.
The changes certainly sparked some life into the side as Pablo Sarabia opened the scoring on 13 minutes after turning home Marcos Llorente's cross.
Norway and Slovenia could not be separated after playing to a goalless draw at the Ullevaal Stadion in Oslo.
The visitors did finish the game with 10 men after Miha Blazic was given his marching orders in the 63rd minute.
The point keeps Norway top of Group 4 after three matches played, while Slovenia remain rooted to the bottom with one point from three games.
Serbia made it back-to-back wins in Group 4 after claiming a 1-0 win away to Sweden at the Friends Arena.
The Serbians broke the deadlock on the stroke of halftime, with Luka Jovic volleying home from close range after a knockdown from Strahinja Pavlovic.
