The England duo battled to a 14-5 lead after eight ends of the 10th round and looked to be well on their way to a comfortable win.
But the Namibian pair, John Shelley and Peter Opperman, fought back to snatch a 18-16 lead with just three ends to play.
However, doubles on both the 19th and 20th ends gave them a two-shot cushion going into the last, where the best Namibia could do was a single.
Scotland's Richard Corsie and Alex Marshall recovered from
20-13 down with six ends to play to beat Hong Kong's Mel Stewart and David Tso 28-21 to stretch their unbeaten run to nine.
But Ireland's Stevie Adamson and Sammy Allen, who surrendered their unbeaten run earlier in the day when they went down to Canada, lost out again this time, going down 20-15 to Israel's George Kaminsky and Jeff Rabkin.
England stretched their winning run in the World Triple Championship to eight when they battled to a 26-14 win over Swaziland.
Roy Cutts, Andy Thomson and John Bell made a fine start with doubles on each of the opening four ends, but with 11 ends completed their lead had been reduced to 12-10.
But England counted a six on the next end followed by a double to take a 20-10 lead and they went on to win 26-14.
Bell said: 'There is no doubt that the six came at just the right time. They were getting back at us and the strong wind was making conditions very difficult.'Reuse content