''I don't think this series has been the best cricket we're capable of. This ground has great memories for both teams, so we're looking forward to a nice loud crowd again."
South Africa easily won the only T20 clash of the tour at Eden Park, when legspinner Imran Tahir destroyed New Zealand's lower order with five for 24 to set up a 78-run win.
Du Plessis believes South Africa have been ''a little off the ball" during the ODI series.
''We've been firing at 65 percent on tour, we haven't been consistent enough in the style of cricket we want to play.
''We've got to be relentless in the areas we bowl, and we've been very soft in giving boundaries away.
''With the bat we've not got enough hundreds in the top six (none compared to two by New Zealand).
''That's something we pride ourselves on."
South Africa lost their ODI No 1 ranking to Australia recently. Win tomorrow and they will regain that spot. New Zealand will stay at No 3 on the list, win or lose at Eden Park.