The phrase "huge favour" means doing something kind or helpful for someone to a very large extent.
Sentences with «huge favour»
Hull, who start the weekend just a point above the drop zone, can do themselves a huge, huge favour with a win over the doomed Burnley. (football-bookmakers.com)
Uruguay can do themselves a huge, huge favour on Thursday by taking a win over qualification leaders Brazil. (football-bookmakers.com)