The Saddlers had to weather a late storm after Rhys Oates had put the Stags back in it with eight minutes left and it was a nervy last ten minutes for Michael Flynn's much changed team who had to cope without Danny Johnson and Liam Bennett.
Johnson was on loan from opponents Mansfield so didn't play in the game and Bennett had been recalled on Saturday by parent club Cambridge United
Further changes saw Oisin McEntee starting in defence and forwards Douglas James-Taylor and Andy Williams also getting a start but there was no place for the suspended Hayden White.
Walsall were well beaten in their last game at home to Stockport on Thursday and Michael Flynn was expecting a response from his team.
He certainly got one after they weathered Mansfield pressure from the start of the game to take a half time lead through James-Taylor's neat finish, the youngster again on song for his second goal of the season
Mansfield went into the game in good form, having won two and drew two of their last four games and handily placed in sixth position. Going into this game they had beaten Hartlepool 2-1 away on Thursday
And they looked the more dangerous early on, Walsall starting with a spell of pressure but not able to get any attacks of note going, with Mansfield looking good on the counter attack.
Owen Evans had to be alert as early as the fourth minute when Anthony Hartigan lofted a free kick for Mansfield into the Walsall box which was , met by Ollie Hawkins whose close shot was saved.
Four minutes later a Walsall attack was broken down and cleared to Rhys Oates who made good progress towards Saddler's goal, feeding Kellan Gordon whose cross ust evaded the waiting Stags' forwards.
Another Mansfield counter attack on 11 minutes saw Swan put the ball into the box, it wasn't cleared and Ollie Hawkins fired just wide. Hiram Boateng was also looking threatening for Mansfield and he saw a shot deflected wide.
As quite often for Walsall Tom Knowles was looking the most creative and he had the first shooting chance for Walsall which he fashioned himself as he cut in from the left on 35 minutes but his shot was deflected for a corner.
Against the general run of play though, Walsall took the lead when Andy Williams and Jacob Maddox combined in the box and it took a fortunate deflection towards James-Taylor who made no mistake for his second of the season, taking advantage of his opportunity of a start to press his claim for a regular place.
Knowles fired just wide in injury time as the Saddler's finished the half well and on a high , though Mansfield came back through George Lapslie who also put a shot past the post.
And the Saddlers got the perfect start to the second half when Isaac Hutchinson's corner from the left found the head of Liam Kinsella barely a minute after the break, the giving Mansfield goalkeeper Christ Pym no chance to make it 2-0 and put Walsall on a real high.
When Andy Williams just a few minutes later put a shot just wide from the right hand side of the box it looked like Walsall were coasting the early stages of the second half.
They still had to be on their guard of course, Rhys Oates in particular looking dangerous down the right hand side and creating a chance with a ball inside which had to be twice blocked then scrambled away. But generally Walsall were controlling the game at two up
Liam Gordon was having a great game on the left, twice he got angled shots in, the first on 57 minutes deflected wide and the second on 67 almost finding its way past the defenders and into the net but it just crept wide.
On 75 minutes, with enough time for Mansfield to get back in the game, Boateng floated in a free kick and Ollie Hawkins met it, his shot going just over the bar.
The Stags continued to look dangerous on the counter-attack and reduced the deficit when Kellan Gordon got a cross in for Oates to convert well, with goalkeeper Owen Evans booked for holding onto the ball in the aftermath.
It looked like Walsall might be in for a nervy last ten minutes and so it proved but despite some Mansfield pressure, the defence held firm and all round, this was a good, hard-working performance from the Saddlers against one of the better teams. Mansfield didn't look as strong as Stocport but in Boateng and Oates, always had a goal threat going forward and Michael Flynn will consider this a massive three points.
Walsall: Evans; Gordon; Daniels (c); Monthe; Kinsella; Knowles; Williams (Wilkinson 71); James-Taylor (Earing 86); Maddox (Comley 77); McEntee; Hutchinson
Subs not used: Barrett (GK); Cashman; Allen; Maher
Mansfield: (4-4-2) Pym; Gordon; McLaughlin (O-Toole 62); Hartigan (Maris 32); Hawkins; Perch; Quinn (Bowery 62); Oates; Swan (Law 77); Lapslie; Boateng
Subs not used: Flinders (GK); Anderson; Collin;