West Coast, which had won only one of its previous seven games, piled on 44 points in the first spell to establish a margin that North Otago was unable to match in the second half.
The loss by North Otago means it will have to take on Mid Canterbury at Ashburton in the Lochore Cup semifinal this Saturday.
North Otago co-coach Nigel Walsh admitted the first half was a real surprise.
"We just gave them the first 40 minutes where West Coast came out and threw everything at us. They had a couple of things to play for today. They were playing their last game of the season plus they were playing for one of their team-mates [Brogan Watt] who is in hospital suffering from a brain bleed. We passed on to Cuttie [West Coast coach Sean Cuttance] our sympathy for the player," Walsh said.
North Otago conceded a penalty try in the ninth minute for deliberately knocking the ball down to give the home side an 8-0 lead.
Three minutes later, a North Otago handling mistake turned into a try for the home side.
Then winger Erenimo Tau raced 70m to score for first five-eighth Nik Cumming to convert and take West Coast out to a 22-0 lead.
A couple of minutes later, Cumming sold a superb dummy to score and convert to take West Coast out to a 30-0 lead.
The two teams then went try for try until the halftime whistle as defence appeared to take a back seat.
Walsh said North Otago was impatient and it was costly.
"I don’t think that we were shell-shocked, or whether we were just trying too hard.
"We were too often trying to score from the first phase ball instead of having patience and setting phases together. When we did get three or so phases together, we found holes in their defence and scored a couple of tries. But we just panicked, which was a bit disappointing, really.
"It was one hell of a comeback to get within 12 points of West Coast with 12 minutes to go. I thought we were in for a bit of a sniff.
"The boys played some great rugby in the second half with them showing just what they were capable of doing in the third quarter. If they’d played the same way in the first half, we might have been talking differently now."
Forwards Jared Whitburn and Matt Duff played well, while winger Simon Lilicama also stood out.
In other games, Wanganui retained top spot in beating Horowhenua-Kapiti 20-12, Poverty Bay beat Thames Valley 50-14 to move into the Lochore Cup playoffs, South Canterbury downed Mid Canterbury 14-0, Buller beat King Country 40-38 and Wairarapa Bush beat East Coast 44-22.
In the Meads Cup semifinals next Saturday, Wanganui will host Wairarapa Bush and South Canterbury will play Buller in Timaru.
In the Lochore Cup semifinals, Mid Canterbury will play North Otago in Ashburton and King Country will play Poverty Bay.
- Terry O'Neill
Heartland Championship
The scores
West Coast 54
Erenimo Tau 3, Maleli Mudu, Nik Cumming, Logan Heath tries, penalty try; Nik Cumming 5 con, pen
North Otago 42
Simon Lilicama 2, Jared Whitburn, Matthew Vocea, Samisoni Tongotongo, Ralph Darling tries; Tyron Davies 2 con; Brad McKenzie con
Halftime: 44-14