Superb defence in the closing stages of North One East’s ‘Match of the Day’ produced a superb result for West, who are now eight points clear of the chasing pack with just six games to go.
The Brinkburn side now occupy the play-off place with Pocklington three points ahead in the automatic promotion spot.
However, the Yorkshiremen have to visit Brinkburn on April Fool’s Day in what may become a winner-takes-all showdown.
Penrith arrived knowing their promotion hopes depended on a win and took the initiative from the kick-off when West were judged to have been in front of the kicker.
The visitors launched a series of attacks down the left and opted for a line –out in the corner after West were penalised.
However, scrum half Ryan Painter seized on a loose ball to break clear up the touchline. His kick ahead took play into the Penrith 22 where West forced a penalty of their own which was converted by Zac Southern.
West stopped one dangerous attack when winger Jon Fell broke through the middle, and returned to the visiting half to mount a series of drives from the forwards. Fly half Southern was wrapped up when he tried to make a break and then Peter Youll was stopped just metres short of the line.
However, West kept possession and with the Penrith defence wearing thin, Ryan Painter picked out Rob Thorn with the big winger forcing his way over from short range.
Southern added an excellent conversion from wide on the left to give his side a very welcome 10-point lead.
It wasn’t to last with Penrith capitalising after West No 8 Sam Miller was unlucky to receive a yellow card as he went to take a high clearance. He was beaten to the ball by a flying James Boustead who crashed to the ground with referee Paul Musgrave ruling that the West player had illegally used his shoulder.
Penrith used their scrum advantage to force West back into their own 22 opting to go for a line-out from a penalty with hooker Crag Price touching down from the catch and drive.
Matt Allinson’s conversion reduced the lead to just three points with his side continuing to use their one-man advantage to mount pressure on the home line.
West defended well but with Sam Miller waiting on the touchline for a break in play to resume his duties, the home defence was breached for the second time.
Scrum half George Graham, who shares his name with his father - the former Scotland and Falcons prop, went on the short side from as ruck just inside the West 22.
Winger James McNaughton received the ball on the touchline and he stepped inside the West cover to go over with some ease.
This time Allinson missed with his conversion, but his side went into the break with a 12-10 advantage.
West had conceded two tries when down to 14 men and they showed what they could do with a full complement from the restart.
The forwards attacked up the left with a series of pick and go’s and when the ball was recycled Painter picked out a charging Adam Coates. The prop stepped through one tackle before offloading to Lee Maddison whose deft pass inside left Andrew Rollins clear to charge over from ten metres.
Southern again converted from wide on the left to give his side a 17-12 lead but that was reduced a few minutes later with penalty from Allinson.
With just three point the difference both sides committed themslves to the attack - West having the lion’s share of territory as their scrum provided the base for a number of attacks.
They came closest when Sam Miller, Greg Edwards and Peter Youll were all stopped just metres from the line as West mounted waves of attacks.
Sam Miller did touch down from a five-metre scrum, but Mr Musgrave brought the play back for a reset scrum ruling that the original had gone round full circle. The pressure on the visitors was relieved as yet another attack was stopped under the posts with Dan Boatman judged to have been holding on.
The West skipper had led from the front all afternoon, and he was in the vanguard as the visitors gathered themselves for one last effort to keep their promotion hopes alive.
Joe Rafferty had replaced Carl Miller and one of his first actions was to give away a penalty just outside the 22 on the right.
Allinson’s effort slide wide and that may have been a factor when Penrith were awarded a similar, but closer, shot at goal with just two minutes on the clock. This time they opted to kick for the corner where they took their own ball only for resolute defence to keep them out.
The desperate visitors threw the ball out wide, but again the West centres Peter Youll and Greg Edwards were in no mood to let them through.
And there was massive relief when the Penrith forwards were penalised for going off their feet to give Ryan Painter the opportunity to kick for touch to end a pulsating game.
West head coach Iain Dixon admitted it had been tight but said: “It was a well deserved win in the end. The yellow card was unfortunate as Sam had his eyes on the ball, and his feet on the ground, when their playercrashed into him and that cost us two tries.
“However, our defence throughout was superb with Danny Boatman and Andrew Rollins oustanding and Zac Southern’s goal-kicking was tremendous.”
West: Luke Mallinson, Rob Thorn, Greg Edwards, Peter Youll, Will Hilditch (Joe Wills 18-28 mins), Zac Southern, Ryan Painter, Ross Wood, Andrew Rollins, Adam Coates, John Bunter, Dan Boatman (capt) Carl Miller (Joe Rafferty 70 mins), Lee Maddison, Sam Miller.
Reps not used: Jordan Foulds.
Tries: Thorn, Rollins.
Cons: Southern (2)
Pens: Southern (1)
Yellow: Sam Miller.
Penrith: Ed Swale, Jamie McNaughton, Phil Armstrong, James Boustead, Jon Fell, Matt Allinson, George Graham, Arran Sullivan, Craig Price, Will Morgan, Dan Richardson, Ryan Johnson, Mike Stephens (capt), CallamPoulson, Mike Raine.
Reps (all used:) Ryan Banks, Andrew Holcroft, Ben Littleton.
Tries: Price, McNaughton.
Cons: Allinson (1)
Pens: Allinson (1)
Referee: Paul Musgrave (Durham)