Saints will have to wait another week to secure the League Leaders’ Shield after they went down 30-10 at home to Wigan.
A brace from Tommy Makinson either side of the half gave Justin Holbrook’s side hope after being 14-0 and 18-4 down.
But the Warriors converted their chances to hand Saints their first derby win of the season.
Wigan got off to a good start when Dan Sarginson crossed following Morgan Escare’s break after just four minutes.
Both sides then had a try chalked off before James Roby went close in the 20th minute.
More chances were to come for the home side but each followed a similar pattern – and Wigan duly punished that profligacy to increase their lead.
Joe Greenwood did the damage again, finding a gap on the left hand side to give Gildart some space.
The winger looked wrapped up but he found Sarginson on his outside for his second.
John Bateman slipped out of tackles for 12-0 as the half came to a close but a piece of brilliance between Danny Richardson and Tommy Makinson as the hooter sounded gave Saints a lifeline.
Richardson sent over a pinpoint kick to his winger who out-jumped Gildart, span around and put down in the corner.
It went without saying that Saints needed to score first in the second half – so the last thing they needed was for Tom Davies to stretch out under some weak tackling to extend the Warriors’ lead.
But Saints hit back with Makinson’s second.
Attacking the right hand side LMS hit a pass at pace and produced a wonder offload, under pressure, for his winger.
But after Saints lost the ball in Wigan’s 20, Oliver Gildart went the length of the field to take the lead out to 24-10.
Sean O’Loughlin then scored after he caught a short pass – Williams converting – to hand Wigan the spoils.
Justin Holbrook said Saints didn’t match Wigan in ‘all areas of the game’ as they went down 30-10 in the derby.
“We definitely weren’t good enough,” he said. “We had some chances and I thought it wasn’t so much doom and gloom in the first half. We then created some in the second half but wasn’t good enough to execute them.
“Full credit to Wigan they were better than us in every area of the game.
“Someone said you can’t have it your own way all of the time and they are right. We have beaten them twice and wanted to win the third but I think we underestimated how much they wanted to beat us. They played like that, were better in every area and deserved to win convincingly in the end.
“We were all over the shop at times and Wigan completely outplayed us when they moved the ball around. They looked threatening and we were disjointed for the most part of the game. We have to learn from it and move on.”
He continued: “We’re still in a good spot but we have to make sure we play better than we did tonight. If we don’t we won’t beat anybody. If we do then we are confident we can beat anyone but we have to play well.
“We didn’t do that and full credit to Wigan, they were better than us.”
Tries: Makinson (2)
Goals: Richardson (1 from 2)
Tries: Sarginson (2), Bateman, Davies, Gildart, O’Loughlin,
Goals: Escare (0 from 2), Williams (3 from 4)
REF: C. Kendall
23. Ben Barba; 2. Tommy Makinson, 3. Ryan Morgan, 4. Mark Percival, 19. Regan Grace; 1. Jonny Lomax, 18. Danny Richardson; 16. Luke Thompson, 9. James Roby, 14. Luke Douglas, 13. Louie McCarthy-Scarsbrook, 11. Zeb Taia, 15. Morgan Knowles.
Subs: 10. Kyle Amor, 12. Jon Wilkin, 20. Matty Lees 21. Jack Ashworth.
20. Morgan Escare; 2. Tom Davies, 19. Willie Isa, 3. Dan Sarginson, 4. Oliver Gildart; 6. George Williams, 9. Thomas Leuluai; 25. Romain Navarrete, 7. Sam Powell, 10. Ben Flower, 40. Joe Greenwood, 14. John Bateman, 13. Sean OíLoughlin.
Subs: 8. Tony Clubb, 15. Ryan Sutton, 30. Gabriel Hamlin, 35. Ollie Partington.