Southland's Ash Moeke reduced the gap to 9-3 with his first attempt and despite a wealth of possession, the Steamers were unable to extend their lead by the halftime break with inaccuracy the major problem.
Coach Clayton McMillan reacted to the inaccuracy by changing his inside backs at the break, with Dan Hollinshead replacing Evemy at 10 and Te Aihe Toma taking over at halfback for Jono Kitto.
Baypark's fickle breeze freshened nicely during the break to give the Steamers an added boost in the second 40. Hollinshead increased the Steamers lead with an early penalty but the Stags roared back into the game with a well taken try by No 8 Billy Fukofuka.
Moeke converted to cut the Steamers lead to 12-10 but it lasted one minute, as from the kick-off fullback Te Rangi Fraser kicked ahead and won a 50 metre sprint to the line for a superb individual try.
Hollinshead slotted the conversion from touch to regain the nine point margin. Tiatia then showed his ability to sniff out a half chance by grabbing the ball 55 metres out and outpacing the Stags for a memorable try.
Hollinshead converted to stretch the Steamers' lead to 26-10 with 15 minutes to play and they comfortably held on for a well-deserved win.
Steamers co-captain Culum Retallick was happy with the win but is not getting too carried away.
"We are still finding our feet a bit," he said.
"We have a heap of new guys and a new coach, so there is some excitement there which is good. One of the pleasing things the last couple of weeks has been defence and that is something we are working hard on so we don't leak too many points."
Sam Cane was excited to be back playing in his beloved blue and gold hoops before he is expected to be named on Sunday in the All Blacks squad to contest Rugby World Cup next month.
He hadn't played 80 minutes since the Chiefs quarter-final loss two months ago.
"It was really enjoyable. I am very proud to come from Bay of Plenty and proud to still be associated with the Bay," Cane said.
"I don't get out there as much as I would like but just the group of guys they have here it is always an enjoyable time. There are quite a few guys I have come through age groups, in Bay under-16s and 18s, so to see them progress and have a run out there with them was pretty cool."
Cane was most impressed with the Bay of Plenty defence.
"The pressure we put on them in the first 25 minutes meant we should have come away with more points on the scoreboard, so that was a little frustrating. The defence was impressive and it shows the character of the side.
"It is refreshing and enjoyable to come back to this level."
Bay of Plenty Steamers 26 (Te Rangi Fraser, Chase Tiatia try; Dan Hollinshead 2 cons, pen; Nick Evemy 3 pens) Southland Stags 10 (Billy Fukofuka try; Ash Moeke con, pen)