Tonga eventually managed to hold off a spirited Namibian side led heroically by captain Jacques Burger to win this crunch clash and claim a precious bonus point to boot.
Tonga moved into second place in Pool C with a 35-21 World Cup victory over Namibia in Exeter.
The Sea Eagles' ambitions were seriously dented when they lost their opening game to Georgia 10 days ago in one of the early shocks of the tournament.
But Tonga bounced back from that disappointment by scoring five tries - their most in a World Cup game - to register a bonus-point win and move above Argentina and Georgia in the section.
With group games against Argentina and New Zealand to come, Tonga remain outsiders to make their first World Cup quarter-final, but at least this victory will provide the Pacific Islanders with a dose of confidence for those daunting tests ahead.
Wing Telusa Veainu and flanker Jack Ram both scored twice, and Latiume Fosita once, as Tonga combined some exciting running with their set-piece dominance against the competition's lowest-ranked side.
Namibia's wait for a World Cup win now stands at 16 years and 17 matches since their tournament debut in 1999, but they had the consolation of scoring three tries - two of them from inspirational skipper Jacques Burger - as they came within an ace of their first World Cup point.
Tonga were almost shocked again when Namibia centre Johan Deysel failed to punish an early overlap and the Sea Eagles made the most of their good fortune to score 12 points in as many minutes.
Veainu had been a late replacement for Fetu'u Vainikolo but he made an instant impact when he came in-field to take Fosita's pass and break the Namibian cover defence.
The Rebels wing was hauled down just short of the line after making 40 metres but he rolled over to score and Vunga Lilo added the conversion.
Namibia's tackling was leaving a lot to be desired and it was almost non-existent as Ram raced through unattended from 20 metres after the Tongans had secured clean line-out ball.
It was looking ominous for Namibia, especially with their scrum in such disorder, but a restart charge down ended with wing Russell van Wyk held up inches out before the Tongan line was breached.
Tjuiee Uanivi made good ground after Tonga lost possession and the second-row slipped the ball to wing Trump, who scorched over to the delight of the Sandy Park crowd and provide Theuns Lotze with a simple conversion.
Namibia attempted to put width on the game whenever they could but Tonga's forward supremacy gave them a powerful platform and more quick set-piece ball brought a third try.
Prop Soane Tonga'uiha peeled off the front of a line-out and second-row forwards Hale T-Pole and Joe Tuineau both helped to recycle ball for Fosita, who scored following a smart pick-up off his bootlaces.
Lilo added another penalty for a 22-7 lead but Tonga were denied a bonus point before half-time when the outstretched Veainu put his left hand on the touchline when grounding the ball with his right.
But the fourth try came within five minutes of the restart when Veainu's weaving run punished a sloppy Namibian kick and Ram coasted in for his second try.
Namibia were in danger of being blown away but they were handed a lifeline when Burger was adjudged to have touched down under a pile of bodies and Kotze added the extras from the touchline.
Tonga responded when Veainu burst through again but Namibia were far from finished and found a second wind in the final quarter.
Namibia's forward drove a maul to the Tongan line 12 minutes from time and Burger was again at the bottom of it to claim his second try.
That raised hopes of a sensational Namibia victory, but replacement Kurt Morath eased Tongan fears of lightning striking twice when he became his country's greatest points scorer with a late penalty.