Worcester caused a major shock in the Premiership on Saturday as they beat Saracens 24-18 at Sixways to move five points clear of Bristol.
Ryan Mills scored all of Worcester's points as they gave their survival hopes a huge boost.
Mills kicked three penalties in the opening half-hour as the Warriors moved 9-0 clear before Sarries hit back through Chris Ashton's try.
Mills added two more three-pointers either side of the break, although Alex Lozowski made it a five-point game with 30 minutes remaining.
Having struggled for form in the Premiership, the hosts could have folded but they kept their composure and their fly-half took them to victory.
Schalk Brits did go over late on and Ben Spencer also scored a penalty to give Saracens a losing bonus-point, but it was the strugglers who went away with a vital win.
Mark McCall's men look like a good bet to repeat last season's feat of winning the double, but this game offered Worcester their best opportunity of upsetting the champions. And so it proved. The hosts started impressively and deservedly took the lead after 10 minutes when Mills kicked a three-pointer.
Gary Gold's side were controlling all the forward exchanges, whether it be the scrum, lineout or contact area, and the visitors were conceding penalties as a result.
Warriors fly-half Mills duly added a second off the tee following another infringement before Mike Ellery was yellow carded for a late hit on Francois Hougaard. Mills kicked the resultant chance and the Midlanders had a nine-point buffer.
McCall needed a response from his charges and it came via Ashton, who latched onto Richard Wigglesworth's neat grubber.
However, it was Worcester that had the final word of the half as Mills gave them a 12-7 advantage at the interval.
The respective fly-halves traded penalties at the start of the second period, but the Warriors remained in the ascendency. Their defence consistently put the visitors under pressure and Sarries were duly making uncharacteristic errors. That often led to them infringing inside their own half and Mills was in no mood to miss from the tee.
Three more successful attempts secured the win, despite Brits and Spencer gaining Saracens a losing bonus-point.
Pens: Mills 8
Tries: Ashton, Brits
Pens: Lozowski, Spencer
Yellow Card: Ellery
Worcester: 15 Josh Adams, 14 Bryce Heem, 13 Wynand Olivier, 12 Jackson Willison, 11 Perry Humphreys, 10 Ryan Mills, 9 Francois Hougaard, 8 Alafoti Faosiliva, 7 Sam Lewis, 6 Chris Vui, 5 Will Spencer, 4 Donncha O’Callaghan (c), 3 Nick Schonert, 2 Jack Singleton, 1 Val Rapava Ruskin
Replacements: 16 Jaba Bregvadze, 17 Ryan Grant, 18 Biyi Alo, 19 Tevita Cavubati, 20 Marco Mama, 21 Luke Baldwin, 22 Ryan Lamb, 23 Ben Howard
Saracens: 15 Matt Gallagher, 14 Chris Ashton, 13 Nick Tompkins, 12 Brad Barritt (c), 11 Mike Ellery, 10 Alex Lozowski, 9 Richard Wigglesworth, 8 Jackson Wray, 7 Schalk Burger, 6 Will Fraser, 5 Jim Hamilton, 4 Michael Rhodes, 3 Petrus Du Plessis, 2 Schalk Brits, 1 Richard Barrington
Replacements: 16 Jared Saunders, 17 Titi Lamositele, 18 Juan Figallo, 19 Mark Flanagan, 20 Kelly Brown, 21 Ben Spencer, 22 Max Malins, 23 Marcelo Bosch
Referee: Tom Foley
Assistant Referees: Hamish Smales, Paul Dix
TMO: Keith Lewis