Guptill, playing for the first time in a month after two hamstring injuries, scored 180 not out in the seven-wicket victory over the tourists in Hamilton to level the five-match series at 2-2.
Even the third highest one-day international score by a New Zealander was not enough to earn Guptill a test recall as an opener, coach Mike Hesson said, but the 30-year-old could soon press a case for inclusion in the middle order.
"The test team is performing pretty well at the moment," Hesson told reporters on Thursday.
"Martin and I have talked about test cricket a lot and we certainly gave batting at the top of the order a decent crack. Certainly batting in the middle order is something we are keen to explore and he will do that first with Auckland."
Guptill has played 47 tests, 40 of them in the top order, but has struggled to convert his success in limited overs cricket into the longer format.
While his ODI average is 43.98, and Wednesday's effort gave him all three of New Zealand's top scores in the format, his test average is 29.38.
Guptill's technique has been exposed in test matches, where he has been vulnerable to deliveries moving away outside off stump or short-pitched bowling.
South Africa have been particularly ruthless at exploiting that weakness, with his average against the Proteas in seven tests just 14.38.
He averages 27.49 batting in the top order but in the middle order, where the ball tends to move less, his average is a far healthier 43.37.
Hesson said that while Henry Nicholls had earned the right to hold on to the number five spot that Guptill would be looking to fill, good form in domestic cricket was difficult to ignore.
"It's something that Martin is really keen to have a crack at and certainly something that we are keen for him to explore at first class level first," Hesson told Radio New Zealand.
"Hopefully get some success in that and then ... there might be a (test) opportunity down the line."
The final one-day international is on Saturday at Eden Park with the first test starting in Dunedin on March 8.
(Reporting by Greg Stutchbury; Editing by Nick Mulvenney)
