Castleford Tigers still hold the cards in the fight for Super League survival despite Saturday's 66-12 thumping by Warrington Wolves thanks to a two-point advantage over Wakefield Trinity.
But there are only six points between the rivals on for and against after Wakefield limited the damage against an in-form St Helens.
Should the relegation scrap go down to the wire, Trinity may ultimately get their reward for digging in with the game gone.
Wakefield host Catalans Dragons next before travelling to Leigh Leopards and finishing the season at home to Hull KR.
If Trinity were offered the chance to go into the final round only two points behind Castleford up against a Rovers side with one eye on the play-offs, they may just take it.
Although their situation has improved, Mark Applegarth's team will look back on Sunday's game as a missed opportunity as they fell to a fourth straight loss.
It was not vintage St Helens by any means but they punished Wakefield errors and benefited from an injury to Will Dagger that the home side failed to recover from.
A sixth win in a row leaves the four-time defending champions level on points with Wigan Warriors and Catalans in the fight for top spot.
A 20-6 half-time scoreline flattered Saints after a competitive first half that appeared to be going Wakefield's way as the interval approached.
Trinity were left to rue two costly mistakes in the dying minutes of the half that were duly punished by the world club champions.
St Helens were losing the territory battle but the game took a decisive turn when stand-in full-back Romain Franco dropped Lewis Dodd's high kick under pressure to give James Roby the chance to score against the run of play.
The visitors went in search of a killer fourth try before half-time and got it with the help of Lee Kershaw, the winger spilling the ball on tackle one inside his own 20.
Wakefield had to survive one set but there was a sense of inevitability about what came next.
Sensing blood, St Helens kept the ball alive on the left edge to create the space for Mark Percival to put Jon Bennison over in the corner.
The first half ended how it started with Saints calling the shots.
It took the away side just two minutes to break the deadlock through Jonny Lomax, the half-back backing up a break by Konrad Hurrell after the powerful centre had overpowered Innes Senior.
Wakefield responded positively and were level after eight minutes when Franco ran a good line to hit Luke Gale's pass and give Matty Ashurst an easy finish.
Trinity sensed another half-chance following a break down the left by Senior but he picked the wrong option to the frustration of the home crowd.
It had the potential to unravel early for the hosts after losing Dagger to injury and seeing Tommy Makinson finish spectacularly from Jack Welsby's pass on the back of consecutive penalties.
But Wakefield gave as good as they got with the score at 10-6 and appeared to be growing in confidence against ragged opposition.
Saints were sloppy in possession but like all good sides, they were able to defend their errors.
The same could not be said of Trinity as the game got away from them before the break.
Wakefield were never likely to recover from the double concession but they stayed in the fight and scored first in the second half to threaten an unlikely comeback, Mason Lino and Jack Croft combining to put Kershaw over in the corner.
It was a slick move that highlighted what Trinity are capable of when it clicks. However, they are where they are in the table because it rarely does.
Wakefield were within 10 points of Saints heading into the final half an hour but two quickfire tries ended the match as a contest.
Trinity only had themselves to blame as they continued to shoot themselves in the foot.
Franco came up with another costly error to gift Makinson his second try, committing a cardinal sin by losing the ball on a kick return.
When Dodd backed up a break by Bennison to score Saints' sixth try with 25 minutes still left on the clock, Wakefield were staring down the barrel of a heavy defeat.
But to their credit, they kept going and threw everything at St Helens in the final quarter.
Trinity got their reward in the closing minutes when Kershaw finished Croft's classy offload to score what could prove to be an important try in a tight and tense relegation battle.
Kershaw threatened to make it a hat-trick after breaking clear down the right but he was crowded out by Saints defenders as the champions completed a routine win.
Wakefield Trinity: Dagger, Senior, Franco, Croft, Kershaw, Lino, Gale, Bowden, Hood, Atoni, Ashurst, Griffin, Pitts. Substitutes: Kay, Fifita, Battye, Eseh.
St Helens: Welsby, Makinson, Hurrell, Percival, Bennison, Lomax, Dodd, Lees, Roby, Delaney, Mata'utia, Batchelor, Bell. Substitutes: McCarthy-Scarsbrook, Norman, Royle, Mbye.
Referee: Marcus Griffiths.