Goals in each half from Michelle Stewart and Lucy McConnell put the Northumbrians into the quarter-finals of the competition where they will now face Nottingham Forest at home on Sunday, February 6..
Alnwick, who have been struggling in the league so far this season, went into the match as underdogs, having not played a competitive match for eight weeks.
But with several new signings, they upped their game and never looked to be in any real danger of letting this one slip.
Hopefully, they can now go on and use the victory as a springboard for better things in the remainder of the campaign.
In the Northern Alliance Premier Division, Alnwick Town took all three points with a 1-0 home win over Ponteland United.
The only goal of the game was scored by Sam Eggleston in the first half, keeping them eighth in the table on 26 points. On Saturday (January 29) Alnwick are home to Perch Main Amateurs.
In Division 1, Rothbury earned a point from a —1 home draw with Forest Hall. The visitors took the lead after 15 minutes, but Rothbury were the better side and despite missing several chances, equalised through Dunn in the second half.
The draw places them fifth in the table on 30 points and this weekend they take on bottom of the table Whitley Bay Sporting Club at home.
In Division three, North Sunderland beat Bedlington United Social Club 3-2 with goals from Tom Allan, Chris Gardner and Fraser Tait. The Seahouses side are fifth in the table on 26 points and on Saturday are away to Whickham U23s.
Alnwick Town Development were involved in a thrilling 5-5 away draw with Blaydon Community. Alnwick led 5-1 before Blaydon, despite having a player sent off, fought back to earn a point. They are seventh in the table on 26 points and on Saturday are away to ninth placed Whitley Bay Sporting Club A.
In the North Northumberland League, Amble drew 2-2 away to Newbiggin Reserves whilst Wooler beat Longhoughton 5-1.