Stags topple lacklustre Cards
Goals from Louis Briscoe and Matt Rhead helped to fire the hosts into a two-goal half-time lead, before Joe McNerney reduced arrears with a late strike for the visitors.
Moments later Lee Sawyer was cautioned for an ill-judged lunge on Junior Daniel, before another long throw from Geohaghon caused panic inside the Woking defence and forced Howe to nervously tip the ball over his own woodwork.
Loick Pires then curled an effort from 20 yards out straight into the hands of Marriott as Woking created their first shooting opportunity of the game close to the half-hour mark.
Nevertheless, it was Mansfield who continued to enjoy more possession than their mid-table opponents and create the better openings.
Murray almost put Matt Green through on goal when he sprayed a delightful ball forward from the centre circle, which resulted in Howe having to rush from his goal line in order to connect with the ball before Green.
The Stags captain was again at the heart of the action on 32 minutes, when his corner from the right resulted in Mike Cester clearing from the line to deny Geohaghon a debut goal.
Anthony Howell was booked for a late challenge on Gavin McAllum on the edge of his own box as Woking enjoyed a rare foray deep into the Mansfield half, but from the resulting free-kick McNerney could only curl his free-kick straight into the arms of Marriott.
McAllum came no closer with a low shot from 35 yards out, and on the cusp of half-time Mansfield doubled their lead through striker Rhead.
Despite Woking surviving a series of long throws from Geohaghon in the minutes prior to the interval, the centre-back again delivered his torpedo-like throw two minutes into stoppage time.
After clearing the initial danger, Mark Ricketts attempted to launch a counter-attack with a short, low pass to McCallum, but the Cards midfielder was caught in possession by Daniel, who subsequently played a low ball through to Green.
Stationed on the edge of the area, Green then found strike-partner Rhead with an intricate through ball and with the Woking defence having already pushed out, an unmarked Rhead remained confident and composed as he slotted past the advancing goalkeeper to double the advantage.
Two minutes after the re-start, Meikle cut inside from the left to fire an attempt over the woodwork via the hands of Howe. From the resulting corner, Rhead powered a dangerous header towards goal that had to be hooked away by centre-back Brett Johnson.
The Stags continued to look determined and hungry within their attacking play, but came within inches of being pegged back on 63 minutes when McCallum rattled the woodwork with a ferocious and swerving left-foot drive from the edge.
At the other end, Briscoe was denied by Howe after he powered his way through the middle and tested the Woking shot-stopper’s reflexes with a close range shot from inside the box.
Marriott then denied Jack Parkinson what would have been a fabulous strike as Woking came exceptionally close to a goal on 69 minutes.
The Cards midfielder hammered a thunderous 35-yard free-kick straight down the throat of Marriott, which resulted the veteran shot-stopper having to re-adjust his position in order to palm the ball away and pull off what was a spectacular save.
Substitute Brett Williams fired the subsequent loose ball into the side netting; moments before Mansfield made a double substitution as goal scorer Rhead and the impressive Briscoe were replaced by Speight and Chris Clements respectively.
Green then came within inches of adding a third goal on 81 minutes. Played through by Meikle down the left flank, the Stags talisman dinked a ball over the advancing Woking goalkeeper, which then agonisingly bounced over the woodwork from three yards out.
Green again came close less than a minute later when he fired a low shot straight at Howe, before Woking pulled a goal back as Sawyer hit a hopeful long ball towards the back post and McNerney found the target with a low, right-footed shot.
Marriott then pulled off a superb near-post save using his feet to prevent Betsy from netting an equaliser as Woking attempted to stage what would have been a miraculous comeback.
With most of the 2,061 in attendance at One Call Stadium enduring a sense of nervousness as the game ticked into four minutes of additional time, substitute Speight claimed his third goal of the season to seal the points for the Stags.
The talisman drilled the ball into the top corner from inside the area after fellow substitute Nick Wright showed some superb footwork in holding the ball up on the right touchline and then playing Speight in for what proved to be the killer goal.
Ultimately, Woking will go away from One Call Stadium pleased with their display, though it was Mansfield that recorded the all-important three points.