But it was not without an almighty scare as the hosts opened up a 2-0 lead in the first half before goals from Daniel Ajakaiye, Hassan Ibrahim, Jack Dixon and Antonio Walker turned the tie around.
Southern Combination Premier Division side Saltdean included a host of players with higher level experience, including former Hastings players Matt Whitehead and Curtis Gayler.
See also: * Hastings United chairman: Positive step for new stadium plans* Hastings United boss: That’s why we’ve worked hard to bring Youssouf in* Hastings United beat Three Bridges thanks to Bamba braceUnited made a number of changes with Youssouf Bamba and Lanre Azeez not involved, and Emmanuel Mensah and Sam Adams named on the bench.
While Hastings enjoyed the lion’s share of possession throughout, they struggled to create openings in the first 45 minutes and looked a little vulnerable in defence.
Satdean opened the scoring on 19 minutes when United failed to clear their area and Toby House finished from close range.
They added a second seven minutes later when Gayler tried his luck from all of 30 yards. United goalkeeper Charlie Horlock dived low to his right to make what looked a routine save, but the ball squirmed under his outstretched arms and into the net.
United pulled a goal back on 31 minutes. Ajakaiye sent a looping finish over home goalkeeper Nathan Stroomberg following a swift right wing attack.
Dayshonne Golding, who caused the home defence problems throughout, then cut in from the right only to fire wide of the near post.
Hastings upped the tempo in the second half and took control for the remainder of the game. They levelled things up three minutes after the restart when Ibrahim struck a low shot into the net from 12 yards following another cross from the right.
United got their noses in front for the first time on 57 minutes when a super cross from Golding found Dixon at the far post and he headed a great finish back across the goalkeeper.
Saltdean were now under constant pressure and came close to conceding again as Ajakaiye fired narrowly wide when well placed.
With seven minutes remaining, United made absolutely sure of progressing to the last 16. Another excellent cross from Golding picked out substitute Walker, who finished from around 12 yards.
Saltdean had lost only once at home all season and started the game well, but ended the night a well beaten side as Hastings’ all-round superiority came out on top.
Hastings: Horlock, Beale, Climpson, Christie (Mensah HT), Golding, Lovatt (Adams 86), Ajakaiye, Ogboe (Walker 62), Fielding, Ibrahim, Dixon. Subs not used: Taylor, Makwiramiti. Attendance: 83.