Ronaldo scores on record 181st int'l appearance
The Manchester United star surpassed Sergio Ramos, who has played for Spain 180 times, as the most-capped international for a European nation.
Ronaldo opened the scoring in the 37th minute with Jose Fonte adding a second three minutes into the second half.
RB Leipzig striker Andre Silva completed the scoring in the last minute of the game.
Portugal resume their World Cup qualifying campaign on Tuesday when they host Luxembourg.
They are currently second in Group A, a point behind Serbia but with a game in hand.