St Helens (13) 31
Tries: Soliola, Makinson, Meli, Ashurst, Gaskell
Goals: Foster 5 Drop Goals: Lomax
Salford (6) 6
Tries: Williams Goals: Holdsworth
St Helens came from behind to beat Salford as Royce Simmons's side secured third place in Super League XVI.
In-form winger Danny Williams's early try gave the Reds hope of a first win on Saints soil since 1980.
But Saints, although not at their best, hit back with tries from Sia Soliola and Tommy Makinson before the break, Jonny Lomax adding a drop goal.
Second-half tries came from Francis Meli, Lee Gaskell and Matty Ashurst, Jamie Foster landing five goals.
After losing on all their last 15 trips to Knowsley Road since 1997, Salford were seeking their first away win against St Helens in the summer era.
The Reds were well beaten 56-22 when the two sides met at The Willows back in February.
But, fresh from their first win under new coach Matt Parish, the Reds were the livelier side in the opening quarter at the Stobart Stadium, Williams claiming his sixth try in three matches since his return to league from union.
And they lost joint skipper James Graham too, the fiery England prop venting his fury after having a try disallowed by kicking the ball into the crowd, leaving referee Phil Bentham with little option but to show him a yellow card for his act of petulance.
Salford then lost opposing prop Ray Cashmere for a high tackle on 16 minutes to even up numbers.
And, with Graham back on, Saints eventually had enough to class to pile the points on against their lowly north west neighbours in the end - and earn a play-off semi-final meeting against either Warrington or Wigan.
St Helens coach Royce Simmons:
"James Graham thought he had scored but it wasn't good enough from a captain to kick the ball away like that. He knows that and he apologised to the players at half-time for doing it.
"You can't afford to have anyone in the sin-bin, let alone your captain and one of your most experienced players. He's got a great passion to win and be successful and, at times like that, he lets it get a bit over the top.
"Salford were pretty aggressive. They turned up to do a job for their new coach and came out pretty hard. We got through it and we got no injuries. The game was very stop-start but we did what we had to do."
Salford coach Matt Parish:
"Even though we got beaten by that score, our defence was pretty good. I don't think you can give any team the amount of ball that was given to them, some of it through our own efforts and some of it beyond our control.
"Even in the second half, if we had completed our sets and got to a good kicking game, we could have still have won the game but, with the amount of possession they had it took a lot of gas out of us. With the amount of ball they had, they were probably entitled to have won by 60.
"We're slowly turning the corner. My guys could easily have put their cue on the rack and got beaten by 60 and they didn't. They showed a bit of commitment."
St Helens: Wellens; Makinson, Shenton, Meli, Foster; Pryce, Lomax; Graham, Roby, McCarthy-Scarsbrook, Soliola, Dixon, Moore.
Replacements: Clough, Ashurst, Gaskell, Hale.
Salford: Patten; Broughton, Gibson, Gleeson, Williams; Ratchford, Holdsworth; Cashmere, Smith, Boyle, Henry, Anderson, Wild.
Replacements: Godwin, Jewitt, L Adamson, Paleaaesina.
Referee: Phil Bentham (Warrington).