Twaddle's Auckland Michelin Men had chased Waikato hard in the eights and this was seen as a chance for the Beijing bronze medalist to even the score on his rival.
"I think I was 13, last time I didn't make the start of a race," he reflected afterwards. "Pretty disappointing, but it shows you're never too old to re-learn some lessons, I think."
However, a protest saw the Aucklanders added to the final field, only to struggle home mid-field out in lane nine.
Waikato, also featuring three-time Olympian Toni Dunlop, two-time Olympian Dave Schaper and world championship silver medalist Andrew Matheson, edged the Australian Powerhaw crew by just 0.67s.
"I've been quite surprised," said Waddell. "When we won the eights, I had a number of people texting me and congratulating me on being a world champion.
"It actually feels quite good, I'll take it.
"The standard is still high, and you're fooling yourself if you think you can do nothing and turn up. You still have to be pretty fit."
That calibre of competition is reflected right across the programme, where many of the overseas crews in all age divisions also bulge with world-class performers, reliving their glory days one more time.
Eric Verdonk, 57, won an Olympic sculling bronze at the 1988 Seoul Olympics, but it has taken him three attempts to finally make the start-line at World Masters Games. Two previous campaigns had been hijacked by injury.
His West End crew won the Men's E (55+) coxed four by five seconds.
"For me, I like to win, of course, and I row to win, but I also row for the companionship," admitted Verdonk.
That camaraderie certainly applies to the Kiwi Chicks team, essentially the NZ women's squad from 25 years ago.
Olympic bronze medalists Lynley Coventry (Hannen) and Nikki Mills (Payne) seemed set to reprise their pair combination from Seoul, but were obliged to sacrifice themselves for the greater good of an eight on the same afternoon.
"We came back to do this regatta as an eight, hoping and thinking that we would also do the pair," explained Coventry. "But we didn't really look at the programme."
This was not just a spur-of-the moment get-together for these ladies - they won eight gold medals at the NZ Masters Games as part of their one-year build-up, with Hannen journeying from Nelson to Auckland eight times for training camps and regattas.
"It was really a good reason to get back together and have a nice reunion," said Mills. "I thought it would be quite relaxed, but they've all been competitive."
The pair have still had a very full schedule this week, contesting coxless fours, quad sculls, three different eight divisions, mixed fours and mixed eights, while Coventry will also join husband (and another former Olympian) Bill Coventry in a mixed pair.
The Kiwi Chicks also include two-time world double sculls champion Brenda Lawson, who has been able to re-unite with her old crony, now Philippa Baker-Hogan. They were admitted to the NZ Sports Hall of Fame in 2012.
