Quick tap by Webb

Pretorius offsides and concedes a penalty

Scrum reset

Webb feeds the scrum

Knock on and Ospreys have the opening scrum feed

Ospreys under pressure

Matthew Screech on attack

Jones gets the game underway

The sides are out as the fireworks continue to go off

Welcome to coverage of this opening Pro 12 game and Welsh Derby as 3rd and 4th bottom take each other on.

The Dragons, in 3rd from bottom, are however 14 points off the Ospreys who will overtake Cardiff (5th from bottom) in the unlikely event of a 65 point win.