The Pilgrims put Nuneaton Borough to the sword and led on 15 minutes through Gavin Allott before Walker doubled the advantage seven minutes before half-time.
Walker scored again after the break and Nicky Wroe and Jay Rollins added further goals before Ryan Edmunds scored a late consolation from the spot for Boro.
The Pilgrims, with Walker and Max Wright restored to the starting XI, took the lead on the quarter hour mark.
ALLOTT produced a neat piece of interchange with Rollins and advanced into the box to sweep home the resulting cross from close-range.
George Willis had to be alert to make two saves to deny Edmunds, the second of which was a tremendous low stop from the striker’s 20-yard free-kick.
United doubled their lead in the 38th minute when Rollins motored from his own half before whipping in a delightful ball from the right which was slammed home at the back post by WALKER.
Ben Davies soon teed up Allott for another effort on goal but his drive from the edge of the box flew wide.
United went three goals up two minutes after the break when Wright was chopped down 30 yards from goal and WALKER stepped up to crash the resulting free-kick beyond Belford’s grasp.
The Pilgrims were awarded a penalty on the hour mark when Wright was fouled by Rhys Sharpe and despite Belford saving Davies’ penalty, WROE dived to head home the rebound.
Aaron Birch produced a fine covering challenge to put off Walker as the United winger searched for his hat-trick goal while Allott intercepted a Mike Calveley backpass to crash an effort into the side-netting.
United added their fifth goal in the 72nd minute when ROLLINS worked himself some space before blasting across Belford and into the far corner.
Nuneaton got themselves on the scoresheet seven minutes later when Ashley Jackson was adjudged to have fouled Josh Lundstram and EDMUNDS converted the penalty to deny Willis a clean sheet.
Nuneaton (4-3-3): Cameron Belford; Curtis Obeng, Mike Calveley, Miles Addison, Rhys Sharpe; Cody Prior (Malachi Lavelle-Moore 46), Aaron Birch, James Baxendale; Josh Lundstram, Ryan Edmunds, Taylor Allen. Subs (not used): Luis Morrison, Ty Belford (gk).
Boston (4-4-2): George Willis; Ben Davies, Ryan Qualter, Spencer Harris, Ashley Jackson; Max Wright, Nicky Wroe (Brad Abbott 77), Andi Thanoj, Nicky Walker; Gavin Allott (Jordan Slew 81), Jay Rollins (Andre Johnson 75). Subs (not used): Jonathan Wafula, Dylan Parkin (gk).
Referee: Michael Barlow.