The Africans, bidding for their first ever Rugby World Cup win, trailed 22-7 at halftime but they did notch up a record of their own to give the 10,000-strong crowd plenty to cheer about.
Namibia struggled to adjust to Tonga's pace in the opening exchanges and conceded two early tries when winger Telusa Veainu seared through before flanker Jack Ram jumped out of the back of a driving maul to put his side 12-0 ahead.
Namibia bounced back, however, to score after a sublime offload from lock Tjuee Uanivi released winger Johan Tromp to cross the line.
The try lifted the Africans as they started to match the attacking verve of the Islanders, but twice they fumbled on the final pass.
Tonga struck again when flyhalf Latiume Fosita picked the ball off his bootlaces to score, and an acrobatic leap from Veainu on the stroke of halftime looked like it had given the winger a second, only for video footage to show he was in touch.
It was not long before Tonga claimed the bonus-point fourth try as the fleet-footed Veainu exploded through the line to put Ram in for his second score.
Namibia responded when captain Jacques Burger powered over from a driving maul but Veainu raced through to put Tonga 32-14 in front.
The Africans may not have won the match but they were able to notch up a milestone when Burger crashed over for their third try -- the most Namibia have ever scored in a Rugby World Cup match.
Tonga moved second in Group C, three points behind New Zealand and one ahead of Argentina with games to come against both those sides.
Of concern to the Tongans was an injury to lock Hale T-Pole who limped off and the woeful goal-kicking of fullback Vunga Lilo which will be need to be more accurate if they are to have a chance of beating Argentina in Leicester on Sunday.
Namibia have just over a week to recover before they play Georgia back at Sandy Park next Wednesday.
(Editing by Ed Osmond)
