Jake Speight scored the decisive penalty which spared Mansfield's FA Cup blushes against Slough following a 1-1 draw after extra time of their first-round replay.
The Rebels were the lowest-ranked team left in the competition by the time the clash came round, but Blue Square Bet Premier outfit Mansfield held their nerve - winning 4-1 on spot-kicks after an own goal from Slough captain David Woozley and a Nathan Bowden-Haase header in normal time.
Slough goalkeeper James Warrington made a number of fantastic stops to deny Louis Briscoe in the first half, but could do nothing to stop Mansfield taking the lead through the unfortunate Woozley just before the break.
Lindon Meikle clipped a ball into the box and Exodus Geohaghon's flick-on hit the Slough skipper, who saw the effort loop into his own goal.
The hosts, plying their trade three divisions below Mansfield, equalised through Bowden-Haase, who reacted quickest to Stuart Swift's free-kick which cannoned off the bar.
Mansfield then missed two glorious chances to snatch the game in added time with Speight firing over the bar and Matt Rhead seeing a close-range effort saved by Warrington.
In extra time, Rhead tamely headed into Warrington's arms before Mansfield captain John Dempster saw red for a lunge on Edward Smith - but it did not prove costly as Speight secured a second-round tie against Lincoln.