Pier raced out of the blocks and only a fine save from Liam Giles kept out Rob Speight's effort early on, and the crosses of martin Cooper from the right wing were causing panic in the Traf defence.
Paddy Parke's team deservedly went ahead in the 15th minute when fine approach play down the right involving Cooper and Joe Gallagher saw the ball driven across the Traf goal and Cameron Dobson slammed home his powerful shot past Giles.
To add to Traf's woes, key player Shaun Dodson had to limp off with a leg injury before the re-start, to be replaced by Wayne Aziz at the heart of the Division One champions' defence.
Four minutes later the Pier lads had doubled their lead, Dobson firing home after a Giles had parried a header after another goalmouth scramble caused by a long throw from Ryan Baldry.
Jon Hyde then pulled off a superb save to tip over a looping volley from Traf player-boss Liam Salt, and when the resulting corner was not cleared by Pier Aziz headed over the top from right-back George Rose's cross.
This seemed to kick-start Pier once more and they could easily have made it 3-0 in the 36th minute when the influential Gallagher's shot was blocked by Danny White, and from the resulting corner Niall Gibb's outstanding headed clearance off the line from Sam Hyde's close-range header kept Traf in contention.
Play started to get scrappy before the interval with Baldry and Speight both shown yellow cards, much to consternation of the Pier supporters, who could have been celebrating a superb third in injury-time, Dobson's delightful run seeing him cut in from the left and beat two Traf defenders only for him to fire narrowly wide when it seemed he was set to seal a first-half hat-trick.
After a cagy opening 14 minutes of the second half, with the heat seeming to take its toll on the players, Traf started to step up a gear and just before the hour mark Jon Hyde's superb full-stretch save saw him tip Billy Logan's 25-yard free-kick around the post, and once again from the corner, taken by Sean Exley, Aziz - who was winning everything in the air - headed over the bar.
Within a minute midfielder Gallagher raced through the Traf defence and with Giles wrong-footed shot narrowly side of the target.
Two minutes later a foul was awarded almost 30 yards out from goal to Traf and Logan smashed in a superb free-kick into the top corner to give his side hope of a revival.
Dean Craig's long-range shot on 72 minutes gave Pier a worrying moment, but Parke's team seemed to find new energy and Cooper's gioalbound shot was deflected wide of the Traf goal by Rose and Dobson then had a shot saved by Giles.
The Pier pressure finally paid off in the 77th minute when centre-back Sam Hyde fired home from close range after a corner to restore his side's two-goal lead.
Traf refused to submit and five minutes from time, Joel Ramm pulled another goal back after another goalmouth melee, but despite five minutes of injury-time and plenty of Traf pressure, Pier held on to claim the deserved victory, sub Jamie Hartley making an important block late on to maintain the lead.
Every single Pier player battled hard throughout the 90 minutes for the win, but special mention must go to the marauding runs of right-sided midfielder Cooper and the tireless running of lone striker Speight, who battled for every ball.
West Pier: J Hyde, J Wardle, A Blake (J Hartley 79), S Hyde, D Jones, J Bradshaw (K O'Toole 90), R Baldry, J Gallagher, M Cooper, C Dobson, R Speight. Sub not used: G Reid.
Trafalgar: L Giles, N Gibb, D White, S Dodson (W Aziz 15), G Rose, D Craig, G Thomas, J Ramm, B Logan, L Salt, S Exley (C Dove 85). Sub not used: L Vasey.