Joao Felix also netted a goal in each half, with Joao Cancelo helping ensure Roberto Martinez's side made light work of the start to its qualifying campaign.

It took the visitors just 10 minutes to open the scoring, with Joao Felix rising highest to meet Cancelo's cross from the right and powering his header past a helpless Henri Avagyan.

Ronaldo then got his first of the match in the 21st minute, as he stretched out a leg to poke Pedro Neto's pinpoint cross in from the edge of the six-yard box.

Portugal was playing its first match since Diogo Jota and his brother Andre Silva passed away in a car accident in July, with both teams paying tribute before kick-off.

The goalscorers paid tribute to their late team-mate, while Ruben Neves wore Jota's former number 21 shirt.

Ronaldo’s 21st minute goal created a moment that was not lost on Martinez.

"Diogo Jota is with us. It was special and a sign to keep us going," Martinez said when asked about the significance of the goal.

Portugal's lead stretched to 3-0 11 minutes later, with Cancelo rifling a powerful effort into the roof of the net after Armenia failed to clear its lines.

The UEFA Nations League winner came flying out of the blocks in the second half, with Ronaldo taking just 43 seconds to find the back of the net for a second time.

A loose clearance bounced to him outside the box, and he whipped a brilliant strike into the top-right corner.

Bruno Fernandes struck the right post from close range shortly after, misjudging his slide to meet Nuno Mendes's cross, but Joao Felix got the visitors' fifth goal in the 61st minute, awkwardly bundling in a deflected delivery at the near post.

Tigran Barseghyan eventually put Portugal under some pressure, with Diogo Costa called into action with some routine saves, but Martinez's side remained resolute.

Martinez was thrilled to get off the mark with a convincing victory.

"It's important to start well, to hold on to the game, and we did that," he said.

"The attitude was exemplary, we controlled the game, had a good rhythm, and after scoring the first goal, it was another game we also controlled with great discipline, because we kept trying to score and keep the goal clean.

"Overall, it was a complete performance. It's not easy to get to Armenia and prepare for the game, but I already said in the preview that the players' attitude and work during training were very good.

"And the result came from our performance. Now, we have to bounce back well, because Hungary at home will be another challenge."