Portugal's Goncalo Ramos scored a hat-trick on his first World Cup start to help his side beat Switzerland 6-1 on Tuesday and send them through to the quarter-finals for the first time in 16 years, setting up a clash with Morocco.

Portugal coach Fernando Santos benched skipper and all-time top scorer Cristiano Ronaldo, tasking Benfica forward Ramos with leading the line despite the 21-year-old making his debut just three days before the World Cup in a friendly.

Ramos had played only 10 minutes as a substitute in Qatar but the youngster looked like he belonged on the big stage with a memorable performance for Portugal who did not miss Ronaldo - a late substitute who had a goal ruled out for offside.

Ramos opened the scoring in the 17th minute by picking up Joao Felix's incisive pass before blasting the ball from a tight angle into the top corner to put the Portuguese ahead.

Portugal doubled their lead through skipper Pepe when the 39-year-old timed his leap to perfection to rise above the two Swiss centre backs and head home from a Bruno Fernandes corner in the 33rd minute, with Yann Sommer well beaten yet again.

The Swiss keeper did well to deny Ramos his second goal of the half with a fingertip save from a late counter-attack as the Portuguese went in with a 2-0 halftime lead.

But Sommer could do nothing when Diogo Dalot sent in a cross six minutes after the restart, with Ramos in the right place again at the near post to slip the ball between his legs to give Portugal a three-goal cushion.

The Portuguese piled on the misery when they carved open the Swiss defence with another flowing counter-attack in which Ramos found Raphael Guerreiro in acres of space and the full back fired the ball past Sommer to make it 4-0 in the 55th.

Switzerland softened the blow just before the hour mark when defender Manuel Akanji sneaked in unmarked at the far post from a corner to slip a shot home after Portugal failed to clear.

But a vibrant Portugal attack roared back when Ramos was set through on goal by Felix and just when it looked like he had lost the ball with a heavy touch, the forward chipped it over the onrushing Sommer to complete a well-deserved hat-trick.

Substitute Rafael Leao then put the icing on the cake in second-half added time with a curling effort into the far corner as the stranded Sommer's shoulders sank while he watched the ball sail past him into the back of the net.