Both teams then played out a brief stalemate - neither wanting to push too far forward - before Wairarapa grabbed the winner late on. The relief when Pita Rabo eventually scored to make it 2-1 was huge.
"It was just delight to see the ball roll into the back of the net. Amazing," Cowan said.
He was always going to step up and take the penalty as soon as wide midfielder Dale Higham was tripped in the box by a lazy Rovers tackle, but first planned to place the ball to one side of the goalkeeper.
"But I saw the keeper not move so I thought I'd put a bit more on it," he said.
But the ball cannoned off the top of the crossbar behind for a goal kick, with Cowan left standing holding his head.
However, all was forgotten at Rabo's brave finish late in the second half, and captain Cowan was all smiles at full-time.
He had scored all previous penalties he had taken during the season, and got a couple of winning goals in crucial games: "I guess it's all swings and roundabouts."