The phrase "scrappy affair" means a messy and not well-organized event or situation, where things are done in a haphazard or uncoordinated way. Full definition
It was a very scrappy affair that saw PSG squeeze past the lower league side thanks to a Zlatan Ibrahimovic header, and although the French champions were in control for most of the game, it could've gone very wrong if they managed to concede a goal. (squawka.com)