They felt they 'had' the win/game 'sewn up'. [=they felt that they were certainly going to win]
She designs her own dresses and 'sews' in her free time.
He scored a touchdown that 'sewed up' the win/game.
(..) My friend, everything is not well in the life of the hippies. - Do you know that you are a little jodedor? - Probably. It is amusing as they pass those sew in certain moments. I have loved that woman for a lot of time. She has always been very reserved. We have been together... in silence... (..)2007 Into the Wild