Multi-talented back Tipene Reweti scored a hat-trick to put himself in the conversation of season's leading try-scorer with Francisco Field.
Another player in that discussion is Jack O'Leary, who made some big busts in the midfield, while Jacob Gedye – the young lock who is the son of co-coach Russell Gedye – grabbed a double.
"Russell and I were really happy with them, the defence they showed was unreal," Cosford said.
The scoreline blowout was not because Old Boys didn't have chances – in fact they pounded Metro's tryline for sustained periods.
"When the boys had to do the d[efence], they really d'd up," Cosford said.
"It broke [Feilding's] spirit a little bit."
By contrast, when it was their opportunity, Metro were able to maintain possession – sometimes for up to 25 phases – to get the position to put players over the chalk.
"I think they're hopefully peaking at the right time," Cosford said.
"Got a bit of confidence about them now.
"They know they have to go wide, and do the work up front first.
"To see them putting phases to phases without mistakes is really heartening."
But looking to test that resolve will be Feilding Yellows, who this time made absolutely no mistake in their semifinal with Dannevirke Sports Club, winning 38-14.
Back on July 4, the Yellows had blown a 19-5 lead to lose 21-19 to Dannevirke after putting on all their bench players, but rebounded the following week with a 24-12 win over Metro at Cooks Gardens.
Metro were behind the 8-ball but came back in the second half to tie it 12-12, before the Yellows scored two more tries to take the game away, after the home side had blown about four scoring chances out wide.
"They're really our bogey team. Since I've been involved, we've lost to them three times," Cosford said.
However, since that game, Metro's execution with ball in hand has been much better, and they will be looking to send out several departing players as winners – like halfback Chris Ferguson, who has played for the team for the past five years.
Early rumours suggest the Marist and Kaierau clubs will be the main destinations for the handful of young men transferring to adult rugby next season.
