Wigan Warriors' quest to defend their Super League title took a blow after a shock 16-8 defeat by the already-relegated Bradford Bulls on a Sunday of surprise results.
Title rivals Warrington Wolves were also humbled at home by Wakefield Wildcats 40-26, but the Bulls, whose relegation was confirmed after a loss against Huddersfield Giants last week, produced the performance of the day.
Well-worked tries from Danny Williams and Joe Arundel put Bradford 12-4 ahead at the break and third-place Warriors could muster little in response in the second half, as a Matty Blythe score sealed it for the home side.
The Wolves remain six points behind table-toppers St Helens after loanee Chris Riley came up with the goods against his parent club for Wakefield.
He claimed a hat-trick, with James Keinhorst, Danny Washbrook, Nick Scruton, and former Gold Coast Titan Richie Mathers each adding tries of their own.
Joel Monaghan did bag one of Warrington's five tries, but the Wildcats sped away in the second half to boost their chances of a mid-table finish.
Elsewhere, Huddersfield drew themselves level on points with Warrington in sixth after toppling Catalan Dragons 38-16 at John Smith's Stadium.
The Giants were always in the driving seat as Jermaine McGillvary and Joe Wardle both notched doubles in an impressive display.
Saturday saw Hull KR rack up 11 tries in a 60-12 thumping of basement club London Broncos, who are yet to pick up a single Super League point this season.
Greg Eden, who was dropped for last week's loss to Salford Red Devils due to disciplinary reasons, redeemed himself by surging over three times, while former St George Illawarra Dragon Michael Weyman grabbed a double.
On Friday, a Zak Hardaker-inspired Leeds Rhinos jumped up to second place after holding on at the finish to record a tense 22-18 victory at Salford.
Hardaker dotted down and kicked three conversions, but the Rhinos were made to hang on as Jordan Walne crossed over for the hosts late on.
A first-half salvo from leaders St Helens proved too much to handle for Widnes Vikings as Tom Makinson and Mose Masoe starred in a 44-22 win.
Makinson notched a hat-trick and Samoa international Masoe -- who left Penrith Panthers last season -- touched down twice as St Helens maintained a two-point cushion in first place.
But it was not all good news for Nathan Brown's side as ex-Panthers star Luke Walsh was stretchered off with a suspected serious leg injury.
In Thursday's game, three tries in the space of 13 minutes saw Castleford Tigers mount a fine comeback to draw 18-18 with Hull FC.
New Zealand-born forward Fetuli Talanoa and Jordan Abdul had helped Hull to a 12-4 lead at the break, but with the game seemingly slipping away, James Clare surged over twice to tie the scores in the second half.
Marc Sneyd could have snatched victory for Castleford, but his conversion attempt after Clare's second try drifted wide.