Jamie Ellis scored two late penalties as Castleford upset champions Leeds, while there were also wins for Huddersfield, St Helens and Hull.
The Tigers had trailed 12-10, having squandered a 10-6 half time lead, with Leeds registering tries through Danny McGuire and Ryan Hall, Hall’s score coming when the home side had Nathan Massey in the sin-bin.
But Ellis kept his cool when Tim Roby pegged the Rhinos twice in the final 10 minutes to secure the win for Ian Millward’s men.
St Helens needed two late tries to beat 12-man Widnes 16-4 at the Stobart Stadium, as Gareth Hock‘s Vikings debut ended in defeat.
The decisive point in the game came on the hour mark when, with the scores locked at 4-4, Widnes forward Ben Cross was sent off and team-mate Jon Clarke sin-binned.
It then took Saints nine minutes of a two-man advantage to get over, through Lee Gaskell, and they wrapped the game up when Francis Meli crossed for his second try late on.
Huddersfield sit top of Super League after they cruised past London 34-6 at the John Smith’s stadium.