Striker Popp, who was ruled out of the Euro 2022 final through injury, made her mark with two clinical headers in the first half.

Klara Buhl pounced on a rebound shortly after half-time to extend Germany's lead, before Morocco's Hanane Ait el Haj and Yasmin Mrabet poked into their own net on separate occasions.

Germany continued to cause problems and completed the rout when substitute Lea Schuller added a sixth, firing it into an empty net after a swift counter-attack on the right.

It was a strong performance from Martina Voss-Tecklenburg's side as they created numerous chances and looked sharp going forward, hitting the woodwork on two occasions and having a goal ruled out for offside.

Despite missing key players Lena Oberdorf and Marina Hegering through injury, Germany maintained their impressive record in the group stages of the competition, losing only once in 25 matches.

Morocco, one of eight teams making their World Cup debut this year, were dangerous in flashes, but they lacked the clinical touch that Germany's Popp provided at the other end.

Germany have scored 16 goals in their past six World Cup games

Popp stars as Germany put down marker

With some of Europe's bigger nations underwhelming in their opening matches, Germany took their opportunity to put a marker on the competition, confirming their position as one of the favourites.

They were ruthless in attack and it was talismanic striker Popp who delivered the early goals in the first half which allowed them to play with creativity and flair as the game wore on.

She was gifted a free header when Morocco goalkeeper Khadija Er-Rmichi missed a cross from Kathrin Hendrich, and later connected with a corner to make it 2-0.

Popp joins the USA's Sophia Smith and Japan's Hinata Miyazawa as the only players to score twice in their opening games and she went off to applause from travelling fans in the stands with 10 minutes remaining.

Morocco, ranked 70 places lower than Germany, were not as poor as the scoreline suggests, as they pressed high and caused problems on the counter-attack.

Tottenham striker Rosella Ayane was an outlet with her pace, while captain Ghizlane Chebbak tested goalkeeper Merle Frohms on a few occasions.

But Germany showed their superiority in the moments when it mattered and could easily have added to their tally.

Germany face Colombia in their second group game in a strong position, while Morocco face South Korea next, hoping to pick up their first points at a Women's World Cup.