Salford 34 (12)
Tries: Rutgerson, Robinson, McGuinness, Haggerty, Coley, Moule
Goals: Hodgson 5
Harlequins 0 (0)
Salford boosted their play-off hopes with a stunning win at the Willows which increases the relegation concerns of struggling Harlequins.
Sean Rutgerson opened the scoring on 10 minutes before the impressive Luke Robinson escaped a two-man tackle for a dazzling try just before half-time.
The Reds continued their dominance after the break with Kevin McGuinness and Gareth Haggerty touching down.
Andy Coley and Aaron Moule added further scores to seal victory.
Salford were inspired by scrum-half Robinson and his play guided the Reds to their first win in four games.
Quins however, are just one point ahead of resurgent Wigan and five in front of basement club Wakefield - who take on Castleford on Saturday.
Salford coach Karl Harrison:
"We've been in the top six from round one, and we will not drop out now. "We are not thinking of whether we will be in the top six but how high up we will be.
"We changed the formation offensively tonight, and that suited Luke Robinson. It gave him more running options, and we benefited from that."
Harlequins coach Brian McDermott:
"This is not a huge setback. It's just a stumble. And to progress, we have to get through it. "Salford were very good defensively, and we found it hard to break tackles. We dropped too much ball when we got in good positions."
Salford: Fitzpatrick, Hodgson, McGuinness, Moule, Langi, Dunemann, Robinson, Rutgerson, Alker, Lima, Coley, Littler, Charles.
Replacements: Highton, Haggerty, Gower, Wilshere.
Harlequins RL: McLinden, Wells, Gafa, Smith, Bradley-Qalilawa, Dorn, Leuluai, Mills, Randall, Heckenberg, Noone, Hopkins, Paul.
Replacements: Williams, Haumono, Budworth, Tookey.
Referee: P Taberner (Wigan)