Loanees Ben Thompson and substitute David Wheeler got their first Pompey goals, while Oli Hawkins and Jamal Lowe were also on the scoresheet in the comfortable 4-0 victory.
Millwall loan man Thompson got the opener three minutes before the break, that came after Ayo Obileye had hit the post for the Magpies on 25 minutes.
The Blues blew Maidenhead away after the restart, with Hawkins, Lowe and Wheeler finding the net.
Here's how fans reacted to Pompey's progress on Twitter...
@johnhorneartist - Pompey, a brilliant win lads,you've done us fans proud, you truly have and to go through to next round of FA Cup. Well done lads. It's made my Saturday.Â Â
@MrKevinPrior2 - So glad we came out of that unscathedÂ Â
@FourOneTwice - We're going to WembleyÂ Â
@adrianthompson7 - Que sera sera!!!Â
@WooStewd - Great to see Linvoy! Well done KJ - Players are in the zone!Â Â
@BeePFC2000 - What a game. Keep it up. Onto the next game now. PUP POMPEYÂ
@samstephensuk - And another clean sheet. Records are being broken.Â Well played. PuPÂ