Twilight: Breaking Dawn - Part 2 has debuted its first preview clip.

The short teaser video, released through Yahoo! Movies, shows Bella (Kristen Stewart) testing out her new vampire strength against Emmet Cullen (Kellan Lutz) in an arm wrestle.

"Well done Bella - I've never seen a newborn show that kind of restraint," says Jackson Rathbone's Jasper. In the preceding scene, Bella switched her red vampire eyes back to brown to fool her father into thinking she is human.

After playful taunting from Emmet, Bella decides to prove that she's a physical match for the rest of the Cullen vampire clan.

The Twilight cast officially kicked off promotional duties for Breaking Dawn - Part 2 this week, with Pattinson jetting to Australia and Stewart turning out for the Japanese premiere.

Pattinson recently branded his sex scenes with co-star and girlfriend Stewart as "ridiculous".

"The sex scene in this one is pretty ridiculous as well. It's just because you're shooting stuff to be PG-13, so you have to think of inventive ways to make something sexy," he said. "It's meant to be the greatest vampire sex you've ever had."