The Tanners marched into the next round of the FA Cup (sponsored by E-ON) with a fine battling performance against a side one level above them.
If the first half of the match on Saturday did not amount to much in the first part of this drama, this was certainly put right in the replay.
Within the first minute the visitors forced a corner which was well cleared.
The ever lively Marc Charles Smith broke away and only a good defensive tackle stopped the Leatherhead striker from threatening the Mangotsfield goal.
Steve Sargent's corner was only partially cleared and fell to wingback, Jamie Beer just outside of the area.
His first-time shot, although hit while he was stretching flew low, hard, and importantly pas Michael Green into the net. It was a great goal.
Mangotsfield were rocked back on their heels and fell further behind less than ten minutes later. A low corner saw Dave Stevens net the first of a well-deserved hat-trick from close in.
Although the visitors were chasing the game and applied a good deal of pressure, they created few chances and those that did occur were well dealt with by Tanners keeper Paul Borg, who has taken the opportunity afforded him by Chris Gibson's injury and has kept the number one jersey as his own.
With Leatherhead in ascendance, Charles-Smith could have increased their lead when he was fed by the on fire Stevens and just failed to keep the ball on target with a clever lob from 20 yards.
The Mole Valley side sealed the tie - and a fourth qualifying round tie away to AFC Sudbury on the 28th October - just a few minutes later when a Steve Sargent ball in saw Stevens yet again get a vital headed touch to give the Tanners a three-goal cushion.
There was some question whether a defender had the final touch but the Leatherhead skipper was in no mood to let anyone else claim the second of his hat-trick.
There was some light at the end of the tunnel for Mangotsfield when their pressure - growing ever desperate as the half drew to a close - saw Aaron Cornwall go down a little too easily in the Leatherhead area.
That said, the penalty was given and Robert Claridge converted with ease.
After the break, Mangotsfield came out all guns blazing to overturn a comfortable lead for the Surrey side.
This strengthened Leatherhead squad is now a match for anyone at this level and the defensive work was superb with the midfield digging in to stop anything constructive forming and the defence in which the three centre-backs - Doherty, Duncan and Hendry - were superb catered for everything that was thrown at them.
Back that up with some hard work and commitment from the forward pairing of Charles-Smith and Stevens, this was a superb all-round performance.
When the tired legs of Stewart Holes and Marc Charles-Smith were replaced by Julian Thompson and Scott Bennetts, it was clear that Mangotsfield, despite all of their pressure were crashing out of the Cup.
It was substitute Thompson who created the final goal of the Stevens hat-trick.
The skipper started the move when he battled for the ball midway in the Mangotsfield half and fed Thompson on the right.
Thompson held the ball well and slipped a good square pass in to the area where the predatory Stevens had found a couple of yards of space.
He rarely misses chances like that and buried the ball from 10 yards out. The Tanners were home and dry.
It is a real tribute to the work that Dave Harlow and his management team that a good Tanners squad has evolved into a powerful, confident unit who, on their day, are a match for anyone.
The crowd, a respectable 282 saw a great cup tie and a Leatherhead team who battled for each other and were simply the best on the night.
They can go into their FA trophy match against Rothwell United on Saturday with an air of confidence and a great will to win.
Leatherhead: Borg, Beer, Gray, Hendry (Carpenter), Duncan, Doherty, Holmes (Bennetts), Sargent, Bolger, Charles-Smith (Thompson), Stevens.
Comments: Our rules
We want our comments to be a lively and valuable part of our community - a place where readers can debate and engage with the most important local issues. The ability to comment on our stories is a privilege, not a right, however, and that privilege may be withdrawn if it is abused or misused.
Please report any comments that break our rules.
Read the rules hereComments are closed on this article