Featherstone coach Daryl Powell has praised his side's "huge effort" after they shocked Super League side Castleford in the Challenge Cup.
"It was a huge, huge effort from everyone concerned. I'm delighted for the players, the coaching staff and everyone involved with the club," Powell told BBC Radio Leeds.
"I couldn't be happier. It was a win based on a number of components."
He added: "It's a local derby and Castleford will find it tough to swallow but for us it was a pretty special day."
The Championship side will find out who they face in the fifth-round draw at 1500 BST on Monday.