A motorbike street racer in New Zealand has filmed the heart-stopping moment a rider crashed in front of him, knocking him off his bike and sparking an explosion that damaged shops.The rider filmed the dramatic smash on Sunday during the final lap of the F3 category race one of the Greymouth Street Race on New Zealand's South Island. The footage, shot from a helmet-mounted camera, shows a man riding a Ducati thrown from his bike after rounding a corner and sliding across the middle of the road. The crash happens so fast the rider in pursuit has no chance to avoid the collision and slams into the bike, splitting open its fuel tank which pours petrol all over the road and ignites. As the dazed rider gets up and looks back at the scene of the crash the road is covered in flames and thick black smoke. Safety barriers on the side of the road and shops lining the street also appear to be ablaze. Despite the chaotic scene both riders are understood to have walked away from the crash with only minor injuries.