The game was played at St James’ Park in Newcastle and Spartans won the game after scoring three goals in the first half.
Sado Djalo gave them the lead after 21 minutes, following good build-up play involving McKeown and O’Donnell.
In the second half Newcastle staged a fightback and they scored twice to reduce the arrears through Turner-Cooke and Murioz, but Blyth held on the lift the trophy in front of their jubilant supporters.
After the game a delighted Blyth manager Terry Mitchell said: “That one was for the fans. They have been fantastic all season and we wanted to give them something to celebrate.
"We dominated the first half and went in 3-0 up at half-time, but credit to the young Newcastle lads, because they upped their game in the second half and gave it a go.
"At that point we had to change our game plan and it worked well for us.
"I’m absolutely delighted to have won our first cup since 2017. But it’s not for me, this is for the club.”
Skipper Buddle said: “We did really well in the first half and I don’t think we expected to be 3-0 up at the break.
"We knew Newcastle would react after the break and credit to them for coming back at us and making a game of it.
"I’m a Newcastle supporter and to score a goal at the Gallowgate end, I am just absolutely delighted.
"The fans have been phemoninal all season, we have under-performed this season so to win a trophy at the end of it, we will take that as a positive and move on to the summer.”
Goalscorer Robbie Dale added: “Newcastle were brilliant in the second half, but we had done really well in the first half and we managed to hang on.
"We knew Newcastle would react but we didn’t think they would come back as strongly as they did.
"I’m stepping away from the club at the end of the season so to win a trophy in the last couple of games is a fantastic feeling.”