Cristiano Ronaldo expressed his satisfaction after returning to the Portugal team with four goals in their 6-0 victory over Andorra.
Fernando Santos' side were beaten 2-0 by Switzerland in their first World Cup qualifier but were without talisman Ronaldo on that occasion due to the injury he suffered in the Euro 2016 final.
The Real Madrid star has had a difficult start to the campaign with his club but marked his international comeback in style by netting twice in the opening four minutes.
"We knew that the first goal would be really important against a team which puts 11 players behind the ball," he said after scoring his 42nd career hat-trick to take his international goals tally to 65.
"I know I am important, as are all the other players. I have always given everything for the national team, I feel useful and I'm happy to be back after that injury in the European championship.
"There are eight games to go and we want to win all eight to go to the World Cup."
Portugal play the Faroe Islands away from home on Monday.