Brady said last-minute wins had been a feature of their season and he hoped that would stop now they had booked a home semifinal.
"It's a bit of a worry when it has to go down to the wire like that but I'm pleased with the belief we have as a team that we can pull off a win no matter how bleak it looks," he said.
King was also pleased with the way his team played.
"It was sponsors day here and the place was buzzing. All the feedback I've had was very positive - I think most people thought we deserved to win but all credit to Wellsford ... they never gave up," he said.
Wellsford will play Hora Hora in their last round-robin game knowing their visitors are still in with a mathematical chance of qualifying as their semifinal opponents.
With four teams going into this weekend's round trying to qualify in fourth, only Old Boys fell by the wayside after being humbled 12-50 at Mid Western.
Kamo moved one point ahead of Marist into fourth place after a 28-23 win over the Western Sharks, with Marist losing 26-19 at Hukerenui, but earning a valuable bonus point.
Hora Hora beat Hikurangi 20-12, but thanks to tries to Jared Wendt, Troy Woodman, Robbie Murray and Alan Nesbitt, they also scored a bonus point that keeps them alive in the playoff race.
They will have to beat Wellsford with a four-try bonus point and hope Marist and Kamo draw in their match next week.
There is little chance of that occurring with the other semifinalist almost certainly to be the winner of the Kensington Park match. That won't be the only question going down to the wire with the location of the other semifinal between Mid Northern and Mid Western still to be decided.