There was one late change with Tim Sawyer starting instead of Paul Vinnicombe - who admitted to suffering from a bad dose of “man flu.”
The opening stages saw concerted pressure in the home 22, with Paul Moss taking every opportunity to chip through and test the defence on the greasy surface.
The best scoring opportunity came on four minutes when Andy Cheslin was sent clear in the 22 only for play to be brought back for an over eager forward pass.
Such was West's territorial domination in the opening stages that Sawyer decided to run a penalty in front of the posts. The attempt failed, and could have had repercussions when referee Dean Lythgoe penalised Iain Dixon for stamping at the breakdown. He opted for a good telling off instead of a yellow card.
The next time we were awarded a penalty Moss was given the kicking tee and made no mistake.
That was the only score before the break, although home fly half Steve Wood hit a post with his own penalty attempt on 23 minutes.
The half ended with a rare bit of handbags with full back Dave Richardson sin-binned right on the stroke of half time for swinging a punch at Colin Cheslin.
The second half began with Paul Moss hitting the same post with a 43 rd minute penalty attempt. Penrith eventually cleared the loose ball only to find Davy Tighe on our 22.
The scrum half, playing his last game before ankle surgery next Friday, fumbled the ball but it went backwards and he managed to scoop a pass from between his legs to Iain Dixon.
The full back made ground before feeding Colin Cheslin who surged forward to open up a space for Gareth Kerr. He accelerated into the tackle breaking clear to race up the right wing.
Dominic Morrison was in support on his left shoulder with the pair exchanging passes to draw the defence and send Kerr in at the corner.
Moss was just short with his touchline conversion.
Jamie Connolly replaced Iain Dixon, who had injured a thumb, before Penrith managed a penalty of their own – but only just. Wood slipped in the mud as he took the relatively easy kick and was mightily relieved to see it skid over off the corner of the crossbar.
The next, and final score, should have been West's but Anth Carr, playing in front of his brother who was on the Penrith bench, finished off a great set off attacks by the forwards by knocking-on just as he was touching down.
In the end it didn't matter. Penrith came back with spirit but struggled to mount any concerted pressure and it is West's name which goes into the North/Midlands draw next week.

Penrith: D Richardson, B Western, G Young, M Armstrong, J Nattrass, S Wood, P Newton, R Wilson, M Jali, A Dawson, R Johnson, R Dawson, A Holcroft, I Lewis, M Raine. Reps: T Slack, G Oliver, G Carr, J Sanderson.

Pen: S Wood. Yellow: D Richardson

West: 15 Iain Dixon [Jamie Connolly 50], 14 Andrew Cheslin, 13 Gareth Kerr, 12 Peter Hodgson, 11 Colin Cheslin [Carl Miller 68], 10 Paul Moss, 9 Davy Tighe, 1 Anth Carr [captain], 2 Andrew Dixon, 3 Jon Norris [Chris Stewart 65], 4 Iain Robinson, 5 Tom Dixon, 6 Dan Boatman 7 Dominic Morrison, 8 Tim Sawyer. Reps: 16 Chris Stewart, 17 Paul Vinnicombe, 18 Jamie Connolly, 19 Carl Miller.

Try G Kerr. Con P Moss. Pen P Moss

Referee: Mr Dean Lythgoe [Carlisle]