Matt Chatfield's side earned a place in the Emirates FA Cup First Qualifying Round and a trip to Step 3 outfit Barwell thanks to a slender Preliminary Round replay win over Heanor.
The Bulls had Ross Duggan and Brett Lucas to thank for two superb goals on either side of half-time, before Jesse Vowles's curled effort dragged the Lions back into the game and set up a nervy finish.
The visitors threatened multiple times in the first half, their first real chance coming on 10 minutes when Hugo Warhurst had to stretch his body to tip Jesse Vowles's dipping effort over the crossbar.
That chance came shortly before the Lions appeared to have the ball in the net only for referee Matt Bacon - unconvinced that the ball crossed the line - to rule the goal out.
But, perhaps against the run of play, it were the Bulls to taste first blood, as Buxton fed the in-form Ross Duggan who cut inside onto his right foot before curling low past Jordan Pierrepont, who had done so well two weekends ago to deny him a single goal.
Five minutes later it could have been two to the good when Williams lobbed the ball over the Heanor defence for Duggan to charge towards goal from a tight angle - the forward opted to square for the skipper, but the visitors managed to intercept and prevent what would have been a big chance.
Heanor continued to threaten and Warhurst was needed once again in quick succession, getting down low to knock Richie-Smith's free-kick wide before parrying Jon Jebbison's effort away from danger only seconds later.
The visitors continued the second half in similar fashion, causing the Bulls problems just like they did for the previous 135 minutes of FA Cup football, and they came even closer to drawing level just minutes into the second period when Kyle Hazeldine's close-range effort crashed against the post.
The decisive blow to Heanor's hopes came from a moment of brilliance from centre-half Brett Lucas, who expertly drove a 25-yard free-kick around the wall to double the Bulls' lead.
Instantaneously, however, the Lions clawed their way back into the tie, as Jesse Vowles curled home past Warhurst from just inside the area only four minutes later.
What was a truly entertaining spectacle, although not high in quality, continued to unravel as the minutes wound down, and the tie could have been put to bed with four minutes to play as Jordan Annable crossed in perfectly for Luke Walker at the back post, but the forward's efforts to head back across goal went in vein as the ball floated wide without another connection.
The Bulls held onto their slender lead through seven long injury-time minutes, and earn a First Qualifying Round trip to Southern League side Barwell on Saturday.
Final score | AFC Mansfield 2-1 Heanor Town
Scorers | Duggan (14'), Lucas (64') - Vowles (67')
AFC Mansfield XI | Warhurst (GK), Annable, Darker (Corder 61'), McGuire, Lucas, Hough, Williams, Buxton, Duggan (Warwick 68'), Walker
Unused substitutes | McMillan, Jumma, Stancliffe (GK)
Yellow cards | Darker (59')
Heanor Town XI | Pierrepont (GK), Richie-Smith (Ozmen 84'), Pratt, Craddock, Hall (C), Carlisle, Jebbison, Ball, Sleigh, Hazeldine (Birks 61'), Vowles (Brown 90'+3)
Unused substitutes | Nwadike, Bowler, Tansley, White
Yellow cards | Carlisle (63')
Man-of-the-Match | Hugo Warhurst
Attendance | TBC