It was end-to-end stuff with defence at both ends an optional extra, with referee Aron Brightmore dishing out six yellow cards - five to Waiuku and one for Tauranga's Josh Nelson - maybe to give himself a breather as he clocked up the kilometres from running between goalmouths.
The opening goal in the 9th minute hinted at a spectacular 90 minutes ahead, with City striker Jindrich Hahn leaping up like he's done a thousand times to put some heat on a clearance kick from Waiuku keeper Stuart Ruddell. Only this time the 37-year-old's jump was timed perfectly, with the ball hitting his midriff and ballooning over the stunned Ruddell into the net.
Twelve goals is a lot to fit into any sports column of finite length but, in a nutshell, Waiuku equalised in the 19th minute through Newton Rewi from the penalty spot after Tauranga skipper Mark Van Der Salm clipped Charlie Heather in the area before Tauranga gifted possession away and Neil Heron pounced on the error, with his speculative long range shot deflecting into the net.
Hahn, guilty of missing a couple of one-on-one efforts or giving his support the cold shoulder, made amends in the 36th minute when he threaded his way through the defence and beat Ruddell from close range, before Isaac Bright put Tauranga ahead when he muscled into the area for 3-2.
But from the kick-off, Waiuku striker Derek Sinclair locked it up again when a speculative left foot effort from 20m found its way past out-of-position Tauranga stopper Dale Schischka.
The dust had barely settled before Nelson kept the goals raining down, with his freekick rebounding in off the post a minute after the restart.
But Tauranga's dodgy defence wasn't done for the day, with first Sinclair intercepting a Mark Van Der Salm back pass, rounding Schischka and finding the empty net, and then Daniel Baldwin firing his side into the lead when he volleyed home after more possession was squandered. Sinclair had his hat-trick with his third in the 69th minute.
Tom Livesey pulled one back for Tauranga when he got on the end of a long ball from Irvine but Waiuku extinguished any flicker of a fightback when Nathan Farey's partial clearance was gobbled up by Cody Ralph.
Montgomery was bemused by the capitulation, possibly even slightly embarrassed, pointing out it was not often any side scored five goals at home and got schooled.
"It was a car wreck, a bad day at the office really. Our guys have kept three clean sheets in our last four games and defensively, as I said to you, the back four have been great. But that was an absolute horror show."
Montgomery had targeted the final three games of the round, all against teams below them, as crucial in their push for promotion. Nine points were on offer but Tauranga got just two from goalless draws against Matamata and Fencibles.
They're still fifth in the league but now 10 points off the pace being set by Hibiscus Coast, who downed Warkworth 3-0. How Tauranga respond this Saturday at home to wooden spooners Papakura City will be season-defining in their push to bridge the gap.
"Saturday's a big one [ahead of Monday's Chatham Cup round two clash with Central United] and we'll have Graham [Craven] back, so that'll tighten the ship a bit I hope," Montgomery said.
"We were well beaten by Hibiscus Coast [4-1] early in the season and turned it around and went on a good run, so it's a matter of getting back into it Tuesday and hoping today was a one-off."