It wasn't a good day for the favourites, with New Zealand's other world-class long distance athlete Jo Lawn run down by little-known Australian Kate Bevilaqua in the final 2km of the women's race.
Like Brown, Lawn is building up for Ironman New Zealand in Taupo, hoping to capture a sixth consecutive win, but Bevilaqua's devastating 1h 22m 48s run gave her a slim 10s margin over Lawn.
"I went and got a little bit of a gap and then she kept coming back," the 30-year-old from Perth said.
"I know what she's like at finishing a race, I knew she was behind me and I was scared. I've never hurt so bad in my life but it's my first victory so I'm very excited."
Lawn ground out a big lead on the bike and appeared to be cruising when another Australian, Rebekah Keat, punctured out on the first lap. Christchurch's Gina Ferguson came in 11 minutes behind Lawn in third.
Doe, meanwhile, astonished his rivals with a superb 2h 8m 13s cycle split, putting nearly six minutes into Brown and nearly four minutes on early leader Stephen Sheldrake, who faded badly on the run to finish fifth.
"He rode very well today and was very strong - I just haven't done the speed endurance that these guys have done," Brown, in his first event since pulling out of last year's world championships in Hawaii, said.
"I'm happy with where I'm at - it's not bad for six or seven weeks' training and I've got eight weeks to get better," he added.
Doe could sense Brown catching him on the final lap of the run and stretched every sinew to keep his older rival at bay. His victory comes after a series of agonising misses, finishing second to Richmond in 2006 and second to Australian Craig Alexander in 2005. He was also third in 2003 and fourth in 2004.
Richmond's podium finish was significant in that he held off New Plymouth ITU veteran Shane Reed, who was fourth in 4h 1m 29s.
Reed and Terenzo Bozzone are the favourites to secure the third and final spot in the triathlon team going to the Beijing Olympics, but 2004 Olympian Richmond hopes a late burst can put him in contention.
Yesterday's race attracted sports stars from other fields as well, with former Tour de France cyclist Stephen Swart finishing in 5h 9m 20s and former All Black lock Ian Jones crossing in 5h 17m 57s.
