Indeed, the only real highlight of the match was the half-time appearance of England heroes Jason Leonard and Will Greenwood of Harlequins, and Mark Regan of Leeds.
The one try of the match came from Scotland international fly-half Gordon Ross, who scored all of his team's point. Quins responded with three penalties from their No.10 Andy Dunne, but it wasn't enough to arrest their recent slump in form.
Ross's try came after a hour of turgid play that saw the two kickers trade two penalties apiece and after a debatable scrum decision from referee Shaun Davey, who penalised Harlequins fullback Gavin Duffy for holding on after David Rees had tackled him just outside the 22.
Ross was somehow allowed to scamper through unhindered straight from the scrum and followed up by adding the conversion to give Leeds a 13-6 lead that they would not concede.
Dunne reduced the deficit with his third penalty of the match on 69 minutes as Quins tried desperately to find a gap in the Leeds defence.
However, another debatable decision gave Ross a chance of his fourth successful kick at goal and he took it with ease to put his side seven points in the clear again with just eight minutes remaining.
Quins spurned a late chance to kick at goal as they became more desperate, and despite a long period of stoppage time – including a five-metre scrum – the home side were unable to break through and lost their third home match of the season in disappointing fashion.
For NEC Harlequins:Pens: Dunne 3
For Leeds Tykes:Tries: RossCons: RossPens: Ross 3