Talismanic striker Alexandra Popp scored twice as Germany thumped debutants Morocco 6-0 to launch their Women's World Cup title charge in ominous fashion on Monday.

Popp's 12th-minute header set the Germans on their way in Melbourne and she collected another before the break as the two-time champions romped to the biggest win of the tournament so far.

Klara Buehl added a third in Germany's first attack after the restart before own goals from Hanane Ait El Haj and Zineb Redouani.

A last-minute strike from substitute Lea Schueller completed the rout as Morocco's piece of history -- the first Arab team to play at a Women's World Cup -- ended in humiliation.

On paper it was the biggest mismatch of the group stage, with 70 places separating them in the world rankings, and the gulf was apparent from the off.

The Atlas Lionesses showed glimpses of magic and had a goal disallowed.

However, a fairytale win never looked likely in front of 27,256 fans at Melbourne Rectangular Stadium, a near full-house.

Germany, who won the World Cup in 2003 and 2007, went out in the quarter-finals four years ago.

But since then coach Martina Voss-Tecklenburg has overseen impressive progress, shaping a dynamic, front-foot team which finished runners-up at last year's Euros to England.

They are among the favourites to bag a third title and had their first look at goal when Buehl's low freekick fizzed wide.

They kept pressing and opened their account when Wolfsburg's Popp climbed unmarked to head in her 63rd international goal from a pinpoint Kathrin Hendrich cross.

Morocco were on the back foot but skipper Ghizlane Chebbak had a sniff midway through the half, only for her long-range strike to be comfortably collected.

Lyon's Sara Daebritz found the back of the net with a tidy finish soon after as Germany probed for an inevitable second, but the goal was ruled offside.

The second came seven minutes before the break with Popp, facing away from goal, shouldering home after Buehl's menacing corner.

Buehl then pounced for their third seconds after the restart with Morocco still asleep, rifling home the rebound after Lina Magull hit the woodwork.

In end-to-end action, Anissa Lahmari was denied a historic first World Cup goal for Morocco when she was adjudged offside, before play switched back to the other half and Ait El Haj's own goal.

The defender turned the ball into her own net after a defensive header ricocheted off her shin, with the second own goal coming as Redouani desperately tried to clear off the line.

Schueller made it six from close in as the clock ticked down, with a seventh denied by the offside flag.

Colombia and South Korea are also in their group and play on Tuesday.