Four-wicket hauls from Tarun Nethula and Lachie Ferguson, who picked up a five-for in the previous game, set up Auckland's six-wicket win over Otago, enabling them to finish second on the points table.
Guptill-Bunce (91 off 99 balls) and Raval (63), scoring their second fifties off the match, knocked 91 runs off the target by stumps on the third day, and proceeded to add 69 more runs the following morning. Both batsmen were then dismissed in the space of four deliveries, and Auckland went on to lose Carl Cachopa and Robert O'Donnell for the addition of only six runs, offspinner Josh Finnie accounting for three off the four wickets.
But that would only prove to be a minor blip, as Anaru Kitchen and Donovan Grobbelaar polished off the remaining runs.
In their first innings, though, Otago had produced an impressive batting performance after being inserted. Despite not having the best of starts - the visitors were 37 for 2 and 102 for 4 at different stages - Otago's middle-order strung together some meaty scores.
While Derek de Boorder (78), who scored an unbeaten fifty in the last game, and Michael Bracewell (62) were the top-scorers, each of Otago's batsmen save for Finne entered double figures. At 224 for 7, Otago again dug themselves out of trouble, with de Boorder and Craig Smith (42 off 57 balls) putting on 77 runs. There was also a 63-run partnership for the last wicket between Rhys Phillips (23*) and Jacob Duffy (37).
Guptill-Bunce (88) and Raval (52) set the tone for Auckland's response, contributing 89 runs for the opening wicket. The home team's innings unfolded in a similar manner to that of Otago's, as they found themselves on 255 for 7 and required a 66-run alliance between captain Michael Bates and Kitchen, who smashed a 49-ball 64. Auckland nevertheless were in deficit of 43 runs when they were bowled out.
Central Districts secured six points in a drawn encounter with Wellington in Napier, but it wasn't enough to avoid the last place on the standings.
Wellington had a slim chance of winning the title going into the game. Needing an outright win and as many bonus points as they could muster, they started poorly, folding for 227 on the opening day after being sent in.
Central Districts, driven by fifties from Will Young (78), Greg Hay (51) and Ben Wheeler (55*), secured a 128-run lead. Wheeler, who had picked up three wickets as well, stretched his team's lead by adding 55 runs for the last wicket with Andrew Mathieson.
Wellington's batting was markedly better in their second dig as Stephen Murdoch (112 off 147 balls) found support from fifties from captain Michael Papps (82), Michael Pollard and Luke Woodcock. They set Central Districts a target of 312 after declaring on 439 for 7. Central Districts didn't play ball, batting out 37 overs to score 86 for 1.