Luke Burgess showed a lethal touch in front of goal as he scored twice, either side of a fourth goal this season by the ever-dangerous Nick Haughton.
Farsley pulled a goal back late on through Jake Charles and applied late pressure, but the West Yorkshire side could not deny Fylde a fourth win in the first 11 days of the season.
Fylde boss Jim Bentley made four changes to the side which won at Gateshead on Saturday and, after a quiet opening 10 minutes, the game sprang to life when Kurt Willoughby was played in by Haughton and shot into the side-netting.
The visitors broke the deadlock on 19 minutes, breaking quickly down the right before Salford City loanee Burgess fired a left-foot shot into the top corner.
It was all Fylde as they added a second 10 minutes later, when Haughton maintained his record of scoring in every game so far this season.
The forward chased down the home defence, flicked the ball around the onrushing keeper and shot into an empty net from outside the box.
With Burgess, Willoughby and Nathan Shaw all recalled to accompany Haughton in a dangerous forward line, Fylde continued to threaten but it remained 2-0 at half-time.
The Coasters were clearly out to carry on where they had left off as an off-balance Burgess fired into the side-netting within seconds of the restart.
The home side then looked to hit back, but experienced keeper Chris Neal was in fine form to deny Davy Syers on 55 minutes.
Both sides had chances to score the next crucial goal and it went Fylde’s way on 81 minutes.
The impressive right-side partnership of Luke Burke and Shaw linked up well, and when the ball was played into the middle Haughton flicked on for Burgess to find the bottom corner for his third goal in the competition.
Farsley pulled on back from a set-play five minutes from time, when Charles pounced to finish a goalmouth scramble.
There were a few nervy moments for Fylde during five minutes of stoppage time, particularly when Adam Clayton struck a post, but Bentley’s side held firm to take their place in Thursday’s draw.
Fylde: Neal, Burke, Conlan, Nolan, Pond, Whitmore, Philliskirk (Lussey 85), Haughton (Hulme 82), Burgess, Shaw, Willoughby; subs not used: Johnstone, Mondal, Tollitt, Perkins, Byrne.
Farsley: Kelly, Richards, Walton, Allan, Ellis (West 79), Clayton, Byrom (B Atkinson 25), C Atkinson, Spencer, Charles, Syers (Parkin 59); sub not used: Bower