Matt Dodd stunned the home support and himself as his usual deadly accuracy from 12 yards was amiss and the visitors then rubbed salt into the wound with two swift goals of their own.
Ricky Johnson dragged Leamington back into the game with his sixth goal of the season before a third Guiseley goal before half-time left Brakes facing an uphill battle in the second half.
Dodd ensured there was something to play for, atoning for his earlier penalty miss, but Paul Holleran’s side could not find the elusive third goal.
In a bright start to the game, Liam Daly headed narrowly wide from a free-kick after the returning Dodd was fouled on the right wing.
Having missed the last two games through injury, the speedy winger was presented with the opportunity to fire his side into an early lead when his pass set Joe Magunda up for a first-time shot that struck the arm of Danny Boshell in the 12th minute, but he fired wide from the penalty spot for the first time in his Brakes career.
Wayne Brooksby whipped in a free-kick that Tony Breeden claimed at his near post and the Brakes keeper was back to his heart-stopping best again shortly afterwards, dribbling past a Guiseley attacker on the edge of his area before clearing.
However, he was powerless to prevent the opening goal in the 18th minute.
A corner to the far post was half-cleared and the resulting shot from the loose ball took a deflection before looping to the far post where Danny Forrest had the simple task of heading home his first goal since returning to the club from Workington.
Brakes barely had time to regroup before Mark Bower’s side doubled their advantage, debutant Danny Hall rising unmarked to thump home a header from another corner.
Johnson, who had stepped off the bench earlier than anticipated after Will Green sustained a groin injury, did well to get a header on target under pressure from a free-kick.
A smart move that began out on the right between Dodd, Lee Chilton and Jake Heath saw the Walsall loanee almost slip a perfect ball through for Chilton, only for Hall to steam in with a fine challenge to put the ball behind for a corner.
As the players prepared for the kick to be taken, Ben Parker fell to the ground claiming he had been struck in the face by Joe Magunda but referee Simon Barrow was unimpressed, speaking to both players before allowing the game to continue.
Johnson provided the New Windmill Ground crowd with hope when he nodded home just short of the half-hour mark after Daly helped a corner back into the six-yard box.
The visitors continued to look the more dangerous side going forward, though, and Breeden had to be at his best again to spring across goal as Gavin Rothery curled in a shot following a block by Daly.
The respite was only brief, however, as from the corner a shot struck the post and defender Jack Rea was handily placed to fire home the rebound.
Chilton did well to turn and fire in a shot inside the box but it was straight at Lions’ keeper Steven Drench.
An early second-half goal was needed to give Brakes a fighting chance and they got exactly that when Johnson was hauled down inside the box.
There was a case for the offender being the last man but Barrow kept his cards in his pocket and Dodd bravely stepped up to atone for his first-half miss, firing low to the keeper’s left to half the deficit.
Breeden was again in action at the other end denying Rothery, and there were several timely blocks in the ensuing scramble.
The Brakes keeper made an even better save when he flung himself across goal, sticking out a boot to keep out the ball as a clearance hit a Guiseley player and looped back towards goal.
Rothery forced another save from him before Leamington upped the ante in search of a late equaliser, but the closest they came was when Johnson’s back-header dropped just wide of the upright.
brakes: Tony Breeden, Luke Connolly, Stephan Morley, Joe Magunda, Liam Daly, James Mace, Matt Dodd (Josh Hawker, 81), Jake Heath, Lee Chilton, Will Green (Ricky Johnson, 7), Luke Bottomer (Stefan Moore, 65). Subs not used: Josh Green, Lewis Fenney.
GUISELEY: Steve Drench, Andy Holdsworth, Rhys Meynell, Jack Rea, Danny Hall, Ben Parker, Wayne Brooksby, Danny Boshell, Alex Johnson (Louie Swain, 73), Danny Forrest (Craig Hobson,80), Gavin Rothery (Michael Potts, 84). Subs not used: Jameel Ible, Steve Dickinson.