Max Trimble finished the innings in style by taking 15 runs from the final over.
Boys' High's total looked to be a winning score until a slow start put Rangitoto in the box seat. A hard-hit 101 by Rangitoto skipper Jack Tredray kept his side well in contention.
With nine wickets down Rangitoto needed to score seven from the final over. Trimble then stepped up to produce his second spell of final-over heroics as the visitors managed only two runs before he claimed the last wicket, stumped by Davis.
Also taking on Rangitoto College was Boys' High's colts team, who made easy work of the opposition.
A good bowling effort by the Boys' High Colts, led by Caleb Boswell-Smith, Ben Pepperell and Connor Dyke, saw the Rangitoto Colts dismissed for 106 in 43 overs.
The home team started steadily but then lost four wickets in quick succession. Then, with the game in the balance, a solid partnership between Finn Trimble, Max's younger brother, and Austin Ryburn got their team within sight of victory.
Trimble went on to score a measured 59 not out to win the game for his side in the 30th over.
To date, 45 players have emerged through the Gillette Cup finals to play first class cricket with 11 subsequently going on to represent the Black Caps.
Scorecards
WBHS 1st XI 241 for 9 (Max Davis 61, David Armitt 52, Tim Osbaldiston 22, Max Trimble 17 n.o.) beat Rangitoto College 1st XI 237 (Jack Tredray 101; Sam Clotworthy 3/62, Matthew Lobb 2/35, Max Trimble 2/40); Rangitoto Colts 106 (Caleb Boswell-Smith 3/18, Ben Pepperell 2/17, Connor Dyke 2/32) lost to WBHS Colts 108 for 6 (Finn Trimble 59 n.o., Dante Mitchell 12, Austin Ryburn 12).