The Steamers looked fired up after the break and gained an early three points after big halfback Sitauti controlled the play well to give his team momentum. Kenny Lynn looked lively in the midfield throughout.
A tighthead from the dominant Steamers scrum saw Joe Tupe score in the corner but he was called back for a dubious knock-on call before Ripia kicked his sixth penalty to open up a 12 point lead with 22 minutes left to play.
Southland stormed back through using their big forward pack and crashed over under the posts for a seven pointer scored by Elliot Dixon. Worse was to follow when the Stags scored again through first-five Marty McKenzie and the visitors were ahead 27-25.
Eade stretched it out to 33-25 with two strikes from the kicking tee as the Steamers conceded 20 unanswered points in a dismal 15 minutes.
Bay of Plenty 25 (Kimami Sitauti try; Willie Ripia con, 6 pens) Southland 33 (Talemaitoga Tuapati, Elliot Dixon, Marty McKenzie tries; Scott Eade 3 cons, 4 pen)