There was a hat-trick from Johnston, two from Ditchburn, two for Slater and one each for Calvert and Gibson as the home side ran riot.
It was 6-0 at half-time with Blyth adding a further three after the break.
The victory lifted Blyth to 14th in the table on 45 points.
Meanwhile, Bedlington Terriers went down to a 2-1 away defeat at Boldon CA, leaving them 18th in Division 2 on 33 points.
They still have three fixtures to play, including a home game against Chester-le-Street on Saturday.
In the Northern Alliance League, Cramlngton United continue to head Division 1 and are set to be promoted to the Premier.
Newbiggin, who are currently third on 53 points, are looking to join them in going up as they still have six matches to play.
Bedlington are fourth on 47 but only have three games left to play.
In Division 2, Stobswood are going up as they are 13 points clear of Newcastle East End at the top, but Ashington Reserves look as if they are going to be relegated to Division 3 as they are ten points adrift of safety at the bottom, with Seaton Sluice also in danger of going down.
In Division 3, Newbiggin Central, with four games to play, are in a championship race which looks like going the distance with Walker Central. Walker are just one point behind, also with four fixtures outstanding.,