The initial decision to rule out the goal was subsequently overturned, meaning Otumoetai - and indeed Bigham - went into the break with a two-goal advantage.
But it was a different game in the second half. A goal for the visitors to Grant Harris after just five minutes meant the game was definitely still on. It was much tighter from there, as both sides settled into a holding pattern.
The home side missed a number of chances to put the game away, and had to endure a penalty corner and a couple of curly moments before the industrious Jonathan Simmonds put the game away with less than 10 minutes to play.
He beat two men at the top of the circle and then managed to fire an awkward, bouncing shot that proved too good for the visiting goalkeeper.
Otumoetai will be happy with the result, but Simmonds believes the side should be finishing a far greater number of the excellent opportunities that they are producing.
Bayleys Otumoetai 3 (Andrew Bigham 2, Jonathan Simmonds goals) Waiau Pa Pirates 1 (Grant Harris).