A hat-trick of tries by the Tongan wing Aisea Havili inflicted defeat on Northampton for only the second time since the start of the year and set up an intriguing derby at Gloucester in the Challenge Cup semi-final.
With their M5 neighbours struggling for fit props, Worcester should consider themselves favourites to reach the final, despite having to visit Kingsholm. The power of the Shed is waning, Bristol won there last week and Worcester were hardly daunted at Franklin's Gardens, scoring five tries and holding the lead from the 52nd minute.
For Saints it was a hugely disappointing defeat as their talisman, the impish artist Carlos Spencer, had his full bag of tricks with him and used them to great effect. The showboating that can detract from the former All Black fly-half's game was absent and every feint, dummy and piece of sleight of hand was intended to create space and scores. It was not enough.
The reason was that Worcester expanded their game from the grunt and grind of the troglodyte brigade up front. To begin with they pushed through the pack but halfway through the first half they started to spread the ball wider and the change of tactic had stunning consequences, as they scored three tries between the 27th and 38th minutes.
The French centre Thomas Lombard scored the first, a beautifully timed and weighted pass by Shane Drahm creating a gap, and then Havili cruised home twice as the spare man. The hard yards for his first came from Kai Horstmann, who charged 30 yards before releasing quick ball.
Saints struck straight back from the following restart with a wonderful score by Bruce Reihana, although it was when Spencer received the ball that the defence froze.
On such form Spencer mesmerises tacklers. He drifts towards them, ball held out in front of him, ready to offload, and such is his dexterity that it can go either left or right with a flick of his wrists.
However, four minutes later Havili scored his second, this time from a neat slip inside by Lombard.
A try by Paul Tupai in the 48th minute put Saints in front but Worcester added two more. Dale Rasmussen collected a grubber kick in the 52nd minute and then Havili touched down a length-of-the-field try after Mike Macdonald had burgled a Saints maul.
It summed up Worcester's day. It started with a strong forward, was driven hard by the backs and was finished clinically by a winger.
Northampton: B Reihana; S Lamont, J Clarke, D Quinlan (R Kydd, 78), B Cohen (J Rudd, 78); C Spencer, M Robinson; T Smith, S Thompson (capt), P Barnard (C Budgen, 41), D Browne, D Gerard (M Lord, 56), P Tupai, S Harding (D Fox, 53), M Soden.
Worcester: T Delport; A Havili, D Rasmussen, T Lombard, G Trueman; S Drahm, M Powell; T Windo (M Macdonald, 60), A van Niekerk (C Fortey, 41), T Taumoepeau, P Murphy (R Blaze, 73), C Gillies, S Viali (T Taumoheola, 73; L Fortey, 80), P Sanderson (capt), K Horstmann.
Referee: G Clancy (Ireland).Reuse content