Following their opening 45-17 win over Romania, Ireland collected a maximum of 10 points from their fixtures against the two pool minnows as they ran in 10 tries to one in driving rain which lashed the ground for the entire game.
Back rowers Eric Miller and Alan Quinlan each bagged two tries as Ireland eclipsed its highest World Cup score and previous biggest winning margin, both of which they achieved in a 53-8 drubbing of the United States four years ago.
The result put Ireland one point ahead of Australia, but they still have to play their toughest fixtures against Argentina on October 26 and the Wallabies on November 1.
Both sides committed numerous handling errors in the breezy conditions, but Ireland's great forward discipline on forward thrust prevailed.
It was Ireland's 17th victory from their past 19 games while Namibia were still looking for their first World Cup final win after five fixtures.
Quinlan started the try scoring procession from a rolling maul in the third minute and fullback Girvan Dempsey crossed six minutes later.
Ireland maintained a better than a point a minute pace for the first quarter with Denis Hickie crossing for his eighth try in his last four matches in the 14th minute.
Namibia staunched the try scoring flow while their lock Heino Senekal was sinbinned by Australian referee Andrew Cole for collapsing a maul, but once he returned, prop Marcus Horan and No.8 Miller added further tries in the last 10 minutes of the half.
Centre Corne Powell provided Namibia's sole moment of scoring cheer with a 38 minutes try as Ireland went to the break with a 33-7 lead.
Ireland repeated their five-try performance in the second half with Quinlan and Miller joined on the score sheet by winger Shane Horgan and replacements Guy Easterby and John Kelly.
Paul O'Connell was fortunate not to have been sin-binned for illegal rucking of Namibian lock Archie Graham late in the game. Graham was vigorously trodden on as he lay at the bottom of a ruck, but all Australian referee Andrew Cole was heard to tell O'Connell was "be careful.". The Namibians have confirmed they will cite O'Connell and if he is found guilty he may miss Ireland's game with Argentina and possibly the Australia game as well.
Ireland coach Eddie O'Sullivan had the luxury of resting key players like captain and hooker Keith Wood and halfback Peter Stringer for most of the second half, while players like Miller and Quinlan, who didn't play in the first match, pressed their claims for a regular starting spot.
Final Score: Ireland 64 Namibia 7
For Match Commentary Click Here
G Dempsey; S Horgan, B O'Driscoll, K Maggs, D Hickie; R O'Gara, P Stringer; M Horan, J Hayes, K Wood (capt), P O'Connell, M O'Kelly, E Miller, A Quinlan, S Easterby.
Replacements: S Byrne, S Best, D O'Callaghan, V Costello, G Easterby, D Humphreys, J Kelly
R Pedro; D Mouton, D Grobler, C Powell, V Dreyer, E Wessels, H Husselman; K Lensing, J Meyer, N Du Toit, H Senekal, A Graham, S van der Merwe, W Duvenhage, S Furter (capt)
Replacements: C van Tonder, A Blaauw, H Lintvelt, J van Lill, N Swanepoel, M Africa, M Schreuder.