Walsall keeper Richard O'Donnell saved a last-gasp Adam Rooney penalty as the Saddlers saw off Oldham Athletic to climb into the League One top six.
Oldham had the better of the first half, although the Saddlers hit the post through Andy Taylor's free-kick.
But Walsall improved in the second half, Sam Mantom sidefooting his team ahead on 65 minutes from 18 yards.
Latics' pressure was rewarded when Paul Downing felled James Wesolowski but Rooney's spot-kick was superbly saved.
Febian Brandy lasted 73 minutes on his return to Bescot
following his loan move back to Walsall from Sheffield United,
playing a part, along with Romaine Sawyers and Milan Lalkovic, in the build-up to Mantom's goal.
Walsall now face an even bigger home game on Saturday when they host League One leaders Brentford at Bescot.
VIEW FROM THE DRESSING ROOM
Walsall manager Dean Smith told BBC WM:
"There's been plenty of games when we've played well and not got the three points, so we'll take that tonight when we probably didn't deserve it.
"Sometimes you have to grind out a result. We were holding on at the end and had to man the gates.
"But it was a great penalty save by Richard O'Donnell and I'm really pleased for him. He's an improving keeper who works very hard at his game.
"Sam Mantom took his goal well. It was a good finish from a well-worked move. He's got goals in him."
Oldham manager Lee Johnson told BBC Radio Manchester:
"We didn't get what we deserved, but it was a superb performance from the boys.
"We can't legislate for some of the poor finishing. For some reason, the gods weren't smiling on us and we couldn't get the ball over the line.
"Their goalkeeper was a deserved man of the match. Sometimes keepers win you points and he's won them points.
"But if we keep playing like that, surely it will turn."
Walsall 01 O'Donnell 15 Chambers 03 Taylor Booked 08 Mantom 04 Butler 12 Downing 29 Brandy (Hemmings - 74' ) 07 Chambers 10 Westcarr (Hewitt - 88' ) 25 Sawyers 09 Lalkovic Substitutes 02 Purkiss 06 Featherstone 11 Hemmings 13 Lewis 14 Benning 16 Baxendale 24 Hewitt Oldham Athletic 01 Oxley 05 Kusunga Booked 12 Mellor 08 Smith 03 Grounds Booked 06 Tarkowski 20 Petrasso (Clarke-Harris - 66' Booked ) 04 Wesolowski 10 MacDonald (Harkins - 67' ) 27 Philliskirk (Rooney - 80' ) 19 Dayton Substitutes 02 Brown 09 Rooney 14 Clarke-Harris 17 Rodgers 18 Lockwood 29 Rachubka 30 Harkins
Ref: Fred Graham