The Dragons beat the 2003 Heineken Cup finalists - including Perpignan's big summer signing James Hook - 23-13 at Rodney Parade in Round 2 but the back-to-back home and away defeats by Exeter Chiefs seriously dented their qualification hopes.
"The home win against Perpignan put us in a good position in the group at that stage and we know that to get a result on Saturday we will have to produce a similar performance or even one a fair bit better," said centre Ashley Smith.
"Obviously the 23-19 home defeat by Exeter in the last round was extremely disappointing and took matters out of our own hands but we will go to Perpignan and get the best possible result we can - it is a huge game for us on a number of fronts.
"We are really looking forward to going over there and savouring the fantastic atmosphere they generate while also doing our best to put the pressure on the top two and then see what happens.
"Obviously our aim was always to try and qualify for the knock-out stages of the Amlin Challenge Cup and although we are now relying on others and results elsewhere, this is our final chance to work on our away record in Europe.
"So far we have won one and lost one on the road so this is the final opportunity this season to improve that record.
"But I am sure that while Perpignan's results in the Top 14 are not as good as they would have hoped for they are still a class act - a star-studded side capable of really turning it on when they click.
"All the reports suggest that James has been playing really well for them and as a number of our players know him really well it will be great for us to play against him again."
Perpignan currently top the Pool courtesy of a 13-12 overall try count ahead of the Chiefs while the automatic Pool 4 qualifier could all come down to the Perpignan's trip to Sandy Park a week later.
With the four best Pool winners enjoying home advantage in the quarter-finals, Stade Français Paris, last season's tournament finalists, are well placed to claim one of those spots with 19 points out of a possible 20 in Pool 1 with Brive, the only other club with four wins, on 18 points in Pool 5.
Toulon head Pool 2 just two points ahead of Newcastle Falcons with London Wasps - the only non-French club heading a group - just a point clear of Bayonne in Pool 3 with quarter-final qualification set to go down to the wire.