Auckland hit back when Waikato were caught out after Jordan Trainor's penalty came back off the post, with captain Patrick Tuipulotu quickly crashing over from close range, before the hosts threw one away on their own line and allowed flanker Jordan Manihera to score his sixth try in three games.
Turnovers and missed tackles continued to have a big impact as Marcel Renata's try helped Auckland close the gap to 18-17 at halftime and, after the break, a lack of discipline compounded the many mistakes as the teams traded shots at goal before a penalty try extended Waikato's advantage.
That decisive moment saw Renata sin-binned and eventually saw Waikato capitalise with the match-winning try, although there was little an extra man could have done to prevent Reece from converting a spectacular chip-and-chase.
Auckland 27 (P. Tuipulotu, M. Renata, S. Havili Talitui tries; J. Trainor 3 cons, 2 pens)
Waikato 35 (T. Campbell, J. Manihera, S. Reece tries, penalty try; M. Lansdown con, 2 pens, S. Christie con, pen)
Halftime: 17-18