Diogo Jota scored two and claimed an assist in a fine 3-0 win over Sweden.
Portugal boss Fernando Santos handed him a seventh cap in Nations League game after Cristiano Ronaldo returned to Italy following positive Covid test.
Ex-Wolves man hailed his performance as 'one of my best for my country'.
Portugal are joint top of the Nations League Group Three, level with France.
Liverpool forward Diogo Jota starred for Portugal in their Nations League win over Sweden and insists he felt no nerves deputising for his nation's all-time top-scorer, Cristiano Ronaldo.
The 23-year-old certainly didn't show any sign of pressure as he bagged two goals and an assist in the 3-0 victory over Sweden.
Jota was drafted into the national team by manager Fernando Santos for only his seventh cap and he seized the opportunity with Ronaldo watching on television at home in Italy, following a positive test for coronavirus on Monday.
'It was an excellent night, and one of my best performances for my country,' Jota told goal.com, after the Nations League encounter at Portugal's Estadio Jose Alvalade in Lisbon.
'There was no pressure to replace Ronaldo. We are professionals and, if the boss chooses 11 players to enter the field, these are the ones who have to work.'
Ronaldo, 35, who is said to be showing no symptoms of the virus, left Portugal earlier on Wednesday to finish his isolation period at home in Italy.
The Juventus man's departure allowed Jota to take his excellent club form into the international arena, but Ronaldo's are big shoes to fill, He has scored 101 goals in 167 international appearances.
However, Jota kept his mind on the job and on 21 minutes he provided an assist for Bernardo Silva to open the scoring before netting himself just before half-time and again on 72 minutes.
'I think this is my highest moment,' added Jota, who has made two appearances for Liverpool this term, scoring once against Arsenal, since his surprise £45million move from Wolves.
'I did my best on the field. Joining Liverpool was a big step in my career, and today I started again in the national team, I have to keep doing my best.'
Now a regular international understudy to Ronaldo, few would begrudge Jota his chance. Prior to his Anfield move this summer, the Portuguese scored 33 times for Wolves in 111 appearances.
He won his first Portugal cap as a substitute for Ronaldo in a 6-0 win over Lithuania in Novemebr 2019 and scored his first goal in September this year in a 4-1 win over Croatia.
Last night's win left Portugal top of Nations League Group Three, level on 10 points with France.
In the next round of matches in November, Portugal host France and Croatia play at Sweden.