Mistakes were made early by Coastline when they gave a penalty away in their first set of six which was followed by a stray pass that went wide. Bay of Plenty winger Pesini Tavake showed his speed and set up centre Seta Nalewakalou to cross the line in the first five minutes.
Bay of Plenty raced out to a 26-0 lead at halftime before Coastline launched their comeback bid.
Momentum began to swing the Western Bay's way with strong running by forwards Vance Te Utupoto, Daniel Karauna and Brendon Anderson. This was soon rewarded with a try by Tane Leef and saw the team on the scoreboard in the 60th minute.
Coastline crossed the tryline a few more times but could not chase down the points that were amassed in the first half.
Unuwai said he was rapt that Bay of Plenty had kept their winning streak alive, having beaten Waikato last week.
"We're having a good season so far but there are some areas that we need to work on next week.
"Our defence was good we need keep that up for the full 80 minutes," he said.
Bay of Plenty's next match is against Gisborne East Coast in Rotorua on Saturday.