Walsall's sixth win in their last seven home matches lifted the Saddlers to within four points of the League One play-off positions.
Dean Smith's side took the lead five minutes after the break when Febian Brandy was fouled by Danny Holmes in the Tranmere penalty area.
Will Grigg scored from the spot, the striker's 18th goal of the season.
- Walsall's in-form 18-goal leading marksman Will Grigg has now hit eight in six games - five of them from the penalty spot.
Craig Westcarr then hammered a 30-yard drive past Tranmere goalkeeper Owain Fon Williams seven minutes later.
Walsall had the best of the first half, Jamie Paterson seeing an early effort cleared off the line by Tranmere skipper Ian Goodison, while midfielder Sam Mantom hit the post shortly after the half hour.
Tranmere's main threat came from the pace of Abdulai Bell-Baggie down the left, but Ronnie Moore's former table-toppers were not at their best, slipping back to fifth in the table.
VIEW FROM THE DRESSING ROOM
Walsall manager Dean Smith told WM:
"It wasn't a great spectacle, but we did what we had to do to win.
"Febian Brandy will get the credit for the run to win the penalty, Will Grigg for scoring it and Craig Westcarr for a fantastic strike.
"But I said to the lads 'Don't forget the two great block tackles from James Chambers, another from Andy Taylor and all the headers that our centre-halves won'. It takes all that to win games. You need a team effort."
Live Text Commentary
Full Time The referee blows his whistle to end the game.90:00 +3:08
Foul by Zoumana Bakayogo on Nicky Featherstone, free kick awarded. Free kick taken by Nicky Featherstone.90:00 +0:35
Max Power fouled by Craig Westcarr, the ref awards a free kick. The free kick is swung in right-footed by Liam Palmer, save made by Aaron Mccarey.89:20
Effort on goal by Sam Mantom from long range goes harmlessly over the target.85:39
Inswinging corner taken by Max Power from the left by-line played to the near post, clearance by James Chambers.82:14 Substitution
Substitution Nicky Featherstone is brought on as a substitute for Febian Brandy.81:37
Max Power takes a shot. Save by Aaron Mccarey.80:51
Max Power takes a inswinging corner to the near post, clearance by James Chambers.80:20
Corner taken right-footed by Max Power to the near post, clearance by Sam Mantom.79:43 Substitution
Substitution David Amoo on for Abdulai Bell-Baggie.71:45
Febian Brandy fouled by Danny Holmes, the ref awards a free kick. Direct free kick taken by Aaron Mccarey.70:55
The referee penalises Sam Mantom for handball. Direct free kick taken by Owain Fon Williams.68:57
Mamady Sidibe takes a shot. Blocked by Andy Taylor. Abdulai Bell-Baggie decides to take a short corner.66:22
Unfair challenge on Cole Stockton by Andy Butler results in a free kick. Abdulai Bell-Baggie has a direct shot on goal from the free kick, Aaron Mccarey makes a comfortable save.66:14
The ball is delivered by Liam Palmer, Craig Westcarr makes a clearance.65:21
Foul by Will Grigg on Ash Taylor, free kick awarded. Owain Fon Williams takes the direct free kick.64:48
Foul by Febian Brandy on Zoumana Bakayogo, free kick awarded. Direct free kick taken by Owain Fon Williams.64:34
Will Grigg takes a shot. Save by Owain Fon Williams.63:52
Free kick awarded for an unfair challenge on Will Grigg by Donervorn Daniels. Andy Taylor takes the free kick.62:31 Substitution
Substitution Cole Stockton replaces Michael O'Halloran.
Direct free kick taken by Max Power.59:50 Booking
Booking Max Power goes into the book.59:39 Booking
Booking Craig Westcarr is cautioned.59:10 Booking
Booking Febian Brandy receives a yellow card for unsporting behaviour.58:24
Free kick awarded for an unfair challenge on Abdulai Bell-Baggie by Febian Brandy.57:25
Free kick awarded for an unfair challenge on Zoumana Bakayogo by Febian Brandy. Zoumana Bakayogo takes the free kick.56:09 Goal scored
Goal! - Craig Westcarr - Walsall 2 - 0 Tranmere Craig Westcarr finds the net from 35 yards. Walsall 2-0 Tranmere.55:21 Substitution
Substitution (Tranmere) makes a substitution, with Donervorn Daniels coming on for Ian Goodison.53:19
Free kick awarded for an unfair challenge on Andy Butler by Mamady Sidibe. Paul Downing takes the free kick.52:41
Jean-Louis Akpa Akpro is penalised for a handball. Aaron Mccarey takes the free kick.52:11
Andy Taylor takes a shot. Save by Owain Fon Williams.50:27 Booking
Booking The referee books Danny Holmes for dissent.49:48 Goal scored
Goal! - Will Grigg - Walsall 1 - 0 Tranmere Penalty taken right-footed by Will Grigg and scored. Walsall 1-0 Tranmere.48:21
Penalty awarded for an unfair challenge on Febian Brandy by Danny Holmes.46:32
Jean-Louis Akpa Akpro sends in a cross.45:01
The referee blows his whistle to start the second half.45:00 +1:08 Half time
Half Time The referee blows for half time.42:40
Febian Brandy challenges Abdulai Bell-Baggie unfairly and gives away a free kick. Owain Fon Williams restarts play with the free kick.41:50
Jean-Louis Akpa Akpro is penalised for handball and concedes a free kick. Aaron Mccarey restarts play with the free kick.40:19
Free kick awarded for an unfair challenge on Michael O'Halloran by Andy Butler. Direct free kick taken by Danny Holmes.37:14
Andy Taylor takes a inswinging corner.36:31
Free kick awarded for a foul by Michael O'Halloran on James Chambers. Aaron Mccarey restarts play with the free kick.35:43
Max Power takes a outswinging corner from the right by-line to the near post, Sam Mantom manages to make a clearance.31:37
Craig Westcarr crosses the ball, Jamie Paterson produces a left-footed shot from inside the area that clears the bar.31:11
Sam Mantom takes a shot. Ash Taylor gets a block in.30:24
Sam Mantom takes a shot from a long way out and hits the post.29:55
Ash Taylor fouled by Craig Westcarr, the ref awards a free kick. Direct free kick taken by Jean-Louis Akpa Akpro.28:35
Andy Taylor produces a right-footed shot from outside the penalty area and misses left.27:15
Jamie Paterson takes a shot. Save by Owain Fon Williams.26:33
Zoumana Bakayogo crosses the ball, clearance made by Paul Downing.24:43
Danny Holmes concedes a free kick for a foul on Febian Brandy. Direct free kick taken by Aaron Mccarey.24:12
Corner taken right-footed by Max Power, Andy Butler manages to make a clearance.20:15
The ball is swung over by Zoumana Bakayogo.19:44
Unfair challenge on Abdulai Bell-Baggie by James Chambers results in a free kick. Direct free kick taken by Max Power.15:10
Craig Westcarr is ruled offside. Owain Fon Williams takes the indirect free kick.14:43
Jean-Louis Akpa Akpro is caught offside. Aaron Mccarey takes the free kick.13:47
Corner taken left-footed by Andy Taylor, Owain Fon Williams makes a save.11:24
Andy Taylor crosses the ball, save by Owain Fon Williams.10:21
Andy Butler takes a shot. Save made by Owain Fon Williams.9:23
Free kick awarded for a foul by Ian Goodison on Craig Westcarr. Andy Taylor crosses the ball in from the free kick, clearance made by Zoumana Bakayogo.8:30
Mamady Sidibe takes a shot. Save by Aaron Mccarey.7:46
Jean-Louis Akpa Akpro delivers the ball, Paul Downing gets a block in. Max Power takes a inswinging corner to the near post, Febian Brandy makes a clearance.5:35
The ball is crossed by Abdulai Bell-Baggie, Andy Taylor makes a clearance.3:51
Michael O'Halloran gives away a free kick for an unfair challenge on Sam Mantom. Andy Taylor takes the free kick, Jamie Paterson takes a shot. Clearance made by Ian Goodison.3:20
Mamady Sidibe takes a shot. Comfortable save by Aaron Mccarey.2:22
The assistant referee flags for offside against Will Grigg. Free kick taken by Owain Fon Williams.0:00
The referee starts the match.
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