Nick Haughton’s sublime first-half strike was enough for Fylde to take a massive step towards sealing a National League play-off spot.
Gateshead rallied well and had chances in the second half, but an impressive defensive performance ensured a vital three points which lifted the Coasters above Wrexham into fourth place.
The Tyneside club, who are still chasing a play-off spot themselves, looked to counter in the early stages and Fylde's Jordan Tunnicliffe had to be alert to deal with the threat of Paul Thompson.
Fylde's Danny Rowe fired a free-kick into the wall and then had a golden chance to open the scoring.
From a routine straight off of the training ground, Haughton’s low corner caught everyone out and Rowe pounced but his low effort was deflected behind by Mike Williamson.
Gateshead threatened with a series of free-kicks curled dangerously across goal by Greg Olley but The Heed couldn’t capitalise.
Tom White drove just wide from 20 yards but it was the visitors who broke the deadlock with a moment of individual brilliance after 31 minutes.
Haughton followed up Saturday's goal in the win over Eastleigh by jinking past two Gateshead defenders and firing a dipping shot beyond helpless keeper Aynsley Pears.
The Tyneside club refused to lie down and ended the half strongly but Fylde's defence, led by former Gateshead captain Neill Byrne, were in good form and protected their lead until the interval.
The hosts looked desperate to draw level after the break and keep their play-off hopes alive but their chances were largely restricted to set-pieces.
An opportunity fell to Williamson just before the hour but he couldn't make contact as a corner flashed across goal.
Gateshead's best chance fell to his defensive partner Jon Mellish from another corner.
The ball fell to the centre-half six yards from goal but his rushed effort flew over, a big let-off for the Coasters.
The visitors had chances to extend their lead but neither Byrne nor Haughton could force home the second.
Heed substitute Lewis Maloney threatened with a free-kick from 35 yards but Fylde keeper Jay Lynch didn’t have a save of note to make all game.
Olley should have tested the keeper from a defence-splitting pass late on, but his effort was tame when he found himself unmarked at the back post.
Walters broke at speed in stoppage time but overhit his pass, though Fylde would have no need of a second goal.
The Coasters moved to within three points of third-placed Solihull Moors but crucially now have a nine-point cushion in the play-off zone with just 12 points to play for.
It means Fylde could seal their top-seven place when they visit bottom club Braintree Town on Saturday.
Fylde manager Dave Challinor welcomed the "massive" win but had mixed feelings over his side's performance.
The Coasters boss said: "After the goal we didn't really keep the ball well enough and it was a tough pitch - very firm- which made it a lively game.
"We weren’t at our best by any stretch but we dig in. We changed our shape and got a foothold, weathering a storm.
"We’ve been in the position where we haven’t defended a lead before and we’ve defended very well. A 1-0 win is massive for us.
"We have players at the top end of the pitch who are capable of causing a threat and we know we can cause problems.
"I think the work-rate of our players was brilliant. Danny Rowe will be frustrated not to score but I thought he led the line unbelievably well and worked his socks off, all for the good of the team."
Fylde: Lynch, Birch, Francis-Angol, Tunnicliffe, Byrne, Croasdale, Philliskirk, Bradley, Haughton (Bond 74), Reid (Walters 82), Rowe (Tasdemir 90)
Gateshead: Pears, Tinkler, Devitt (O'Donnell 86), White, Barrow, Williamson, Mellish, Olley, Hunter (Maloney 75), Thomson (Salkeld 66), Rigg