The Saints were decisive winners, being 26-6 ahead at half-time, with two tries from Howard Packman and Ethan Waller coupled with Dickson's goal kicking building up a substantial advantage.
Irish improved greatly after the interval to score two tries through Danny Kenny and Kieran Low but they kept fuelling Dickson's boot whose marksmanship kept Saints in the clear.
Dom Waldouck and Ben Nutley were the stand-out performers for the visitors with Nutley's late try sealing an emphatic win for the Saints.
London Irish's line-up saw Low, Bryn Evans and Declan Danaher all featuring in the pack but captain Shane Geraghty was a late withdrawal with a calf injury. In addition the hosts included 21-year-old twins, Ben and Alex Toolis, as their second row partnership.
Northampton made six changes from last week's win over Gloucester with academy products, scrum half Alex Day and prop Ethan Waller, making their full debuts. Centre Waldouck was again selected as captain.
Northampton began strongly and took a fifth-minute lead with a penalty from Dickson before Irish had their first chance for but Myles Dorrian was off target with his effort.
The opening 15 minutes provided little entertainment as both sides made unforced errors resulting in frequent stoppages. When Low was penalised for offside, Dickson had another chance but his long-range kick fell narrowly short.
Dickson took his next opportunity as the visitors continued to have the majority of possession and territory and were close to being rewarded with the opening try.
Nutley ran strongly along the flank to send Waldouck deep into the opposition 22 but Saints were penalised just as Tom Collins looked a likely scorer.
However Northampton maintained the pressure to win a penalty for a third success for Dickson before they picked up the game's first try.
In the course of their first sustained attack of the match, Irish lost possession in their own 22 allowing Nutley to capitalise by seizing the loose ball.
The flanker ran 60 metres before presenting Packman with an easy run in for a try which Dickson converted before adding another penalty to give the visitors a healthy 19-0 lead.
Irish got on the scoreboard with a Dorrian penalty after Day was penalised and yellow carded for impeding an opponent as he was taking a tap penalty but being reduced to 14 men did not concern Saints.
They immediately responded with a try from Waller converted by Dickson before a second Dorrian penalty just before half-time still left Irish 20 points behind at the interval.
Early in the second half, Northampton, still without Day in the sin-bin, conceded a try to Irish replacement, Kenny, who finished off a line-out drive.
Day returned with no further damage done and the Saints extended their lead with Dickson's fifth penalty.
However Irish were displaying far more spirit than in the first half with Low finishing off another good forward drive but once again for Irish it was two steps forward , one back as Dickson knocked over another goal and then converted a try from the impressive Nutley to emphasise their superiority.
There was a late yellow card for Irish replacement, Ben Lonergan, but Northampton could not take advantage and so were denied a bonus point.
- Sports & Recreation
- Ben Nutley