Kevin Naiqama scored four tries and Adam Swift grabbed a hat-trick as rampant St Helens hammered Hull FC 62-16, while Warrington Wolves put Hull KR to the sword in Super League on Monday.
Saints beat fierce rivals Wigan Warriors on Friday and put on another show three days later, scoring 11 tries in a ruthless demolition of Hull.
It all started so well for the visitors, Joe Westerman and Carlos Tuimavave crossing in the opening 10 minutes before the leaders got into their stride.
Saints took complete command with five tries in just over 20 minutes, Jonny Lomax marking his 200th game for the club with a quickfire double before Naiqama, Swift and Lachlan Coote finished.
Jez Litten went under the posts early in the second half, but Saints turned on the style to run away with it, Swift completing his treble and Naiqama adding another three tries, with Jack Welsby also dotting down.
Second-placed Warrington responded to back-to-back defeats to Saints and Salford Red Devils with a 54-6 drubbing of Rovers.
Tom Lineham and Joe Philbin scored two tries apiece and Stefan Ratchford was on target with all nine conversions as Warrington ran riot.
Wakefield Trinity are up to third following a 26-24 win over struggling Leeds Rhinos, while Wigan Warriors needed a late Zak Hardaker try to beat Salford 30-26.
There were also victories for Catalans Dragons and Huddersfield Giants over Castleford Tigers and bottom side London Broncos respectively.