Tonga left it late to join the Sevens party but they timed their entrance to perfection by beating Canada 14-12 at the death in the Plate final.
Canada looked in control all the way, thanks to tries from Sean Duke and D.T.H. van der Merwe, and a conversion from Philip Mack, but Peasipa Moimoi scored a try and swung over a conversion for Tonga to keep them within touching distance.
With a minute to go, Canada still looked favourites to hold out, but the Tongans ground their way relentlessly towards the Canadian line and Nili Latu eventually went over.
Moimoi held his nerve to knock over the winning conversion.
'You have to give great credit to the guys. We never gave up and kept going until the end,' try-scoring hero Latu said. 'It's still hard to believe what we have achieved.
'To win here is a dream come true. I couldn't have asked for a better finish to the game. It's going to take a while for it all to sink in. It's something I'll always remember when I look back on my rugby career.'
Latu plays for the NEC club in France and was in the right place at the right time to get the touchdown. Unfortunately for Canada, they will rue kicking the ball away aimlessly in the dying minutes after being in control.