The much-anticipated clash between the two powerhouse Dunedin clubs turned into a rout as Caversham fired in four goals in the second half.
"It was probably our best performance of the season," euphoric Caversham coach Steve Fleming said.
"We played smart wet-weather football against a good Technical side, and made lots of goalscoring chances."
Certainly the weather was wild, grounding so many seagulls that at times the birds just watched as passing moves swept through them.
But for the most part Tonga Park had no pools of water and it was only late in the match that the pitch started to cut up.
It did not take long before the large crowd forgot the chill.
After a couple of long-range shots from each side, Caversham broke on the right wing, and as an early run by Ant Hancock dragged defenders forward, Tom Jackson arrived late at the far post and rammed a good goal past keeper Cam Burns in the 27th minute.
Technical struggled to play composed football, with coach Mike Fridge lamenting his side's hesitancy.
But Tech gained a lifeline just before halftime when the industrious Alistair Rickerby drilled a low shot goalwards, and Caversham keeper James Wagget committed the cardinal sin of not getting his body behind the ball, which slid past him to even the score at the break.
Both dressing rooms produced a few decibels of advice as both coaches clarified what was required.
Patrick Fleming must have been listening to his father's team talk.
Just back from university study in the United States, Fleming junior superbly chested then hit a looping volley to re-establish Caversham's lead in the 48th minute.
Technical fought back, but too often good wing play delivered poor crosses, and in general the attack lacked pace.
Caversham frontrunner Jackson struck again with an acutely angled shot in the 67th minute, and Technical's shares dipped lower when Matt Scoles had to take over from the injured keeper Burns.
At that stage Caversham played some superb football involving raking diagonal passes, clever running off the ball and several goalscoring chances that might have produced more than those eventually scored by Darren Overton and Ant Hancock.
Typically Technical battled to the last with Andy Coburn and George Milne competing in midfield, Blair Scoullar showing flashes of skill and fullback Tristan Prattley eager to push forward.
But the defence lacked composure and struggled to achieve a steady platform from which to set up attacks.
By contrast, Caversham impressed, with new signing Tom Schwarz combining well with Tim Horner, and Blair Duncan and Overton hitting well-weighted passes forward on to clever running by Fleming, Jackson and the quick feet of right winger Dave Butler.
Roslyn-Wakari also capitalised on scoring chances as it thumped Southend United 5-0 in Invercargill.
Tim Mather, Dave Shaw, James Watson, Peter Rae and Mike Cunningham scored for Roslyn, which led 3-0 at halftime.
Jason McCone, Nigel Clemett and Tymon Bernard scored the goals in Northern's 3-2 win over Invercargill Old Boys, while Dom Vitesse and Morgan Day scored to lead Mosgiel to a 2-1 win against Green Island.
Gordon Gudd-Anderson scored for the Island.
The next round of the Chatham Cup will be played on 19 June.
