Worcester (7) 14
Tries: Abbott, Sanderson
Cons: M Jones (2)
Harlequins (20) 27
Tries: Robshaw, Stegmann, Masson
Cons: Malone (2), Evans
Pens: Malone (2)
Seb Stegmann's try helped to confirm Worcester's elimination
Worcester failed to progress to the EDF Energy Cup knockout stages with defeat by Quins in their final group game.
First-half tries from Chris Robshaw and Seb Stegmann, plus two Chris Malone penalties, gave Quins a healthy lead over Worcester's lone Jake Abbott try.
Home captain Pat Sanderson scored shortly after his introduction at half time, but the Quins defence held firm.
With the last movement of the match Tosh Masson intercepted and Quins broke away to score.
Worcester never looked like obtaining the four tries that they would have needed to threaten the qualification of Ospreys.
Despite having no chance of progressing to the knockout stages of the competition, Quins surprisingly chose to field a near first-choice side - missing only their England squad members plus Tom Guest, who was a late withdrawal.
Harlequins dominated the opening exchanges and after 10 minutes scored the first try.
From a scrum five metres out Andy Gomarsall fed Jordan Turner-Hall, who set up the ruck from which Robshaw was driven over. Malone converted and four minutes later extended the lead with a penalty.
Worcester responded almost immediately with a try from Abbott which Matthew Jones converted.
The revival in their fortunes was short-lived as Malone kicked another penalty after 24 minutes.
It came as no surprise when they went further ahead on 34 minutes when, from a five-metre scrum, Malone and Stegmann executed a pre-planned scissors movement for Stegmann to score, Malone converting.
With Jones missing a penalty for Worcester, the visitors led 20-7 at the break.
Worcester were desperately poor in the first half so influential captain Sanderson was introduced immediately on the resumption to play his first match of the season.
It almost immediately paid dividends as he crashed over to finish off a strong burst from Sam Tuitupou, with Jones converting.
Nick Evans was introduced by Quins after 47 minutes but now it was the home side's turn to dominate, looking a vastly different team to the one who had performed with so little passion in the first half.
However, as the match drew to a close, Masson intercepted for Quins to round off their victory with a try, Evans converting to conclude the scoring.
Worcester director of rugby Nick Ruddock:
"The wind was against us in the first half so we elected to put them in to bat and back ourselves not to concede - but I was disappointed with the outcome as we conceded two tries.
"I put my captain Pat Sanderson on at half-time and he gave our side a lift as he always does. In the second half I couldn't fault our commitment and passion.
"We were much more physical than in the first half but we lacked the clinical edge.
"Harlequins were not that much better than us but they were the better team because they took their chances and we did not."
Harlequins director of rugby Dean Richards:
"We viewed it as an important game as it is the final one of this stage of matches and I wanted a lot of our players to try a few things out before they have a week off.
"The competition is a worthwhile one but if you lose the first fixture as we did against the Ospreys then you are virtually out of the competition."
Worcester: Latham, Gear, Grove, Tuitupou, Pennell, M. Jones, M. Powell, Mullan, Lutui, Tuamoepeau, Rawlinson, Kitchener, Cox, Abbott, Talei.
Replacements: R. Powell for M. Powell (59), Morris for Tuamoepeau (69), Gillies for Kitchener (50), Sanderson for Abbott (41).
Not Used: Fortey, Crichton, Fellows.
Harlequins: Brown, T. Williams, Masson, Turner-Hall, Stegmann, Malone, Gomarsall, Jones, Botha, Ross, Kohn, J. Evans, Robshaw, Skinner, Davies.
Replacements: Barry for Turner-Hall (19), N. Evans for Malone (47), Lambert for Ross (78), Robson for J. Evans (47), Mcmillan for Davies (38).
Not Used: Fuga, G. Williams.
Ref: Dean Richards (RFU).