Peterhead boss Jim McInally was pleased his side upped their game in the second half to progress in the Scottish Cup.
The Blue Toon saw off Kelty Hearts 3-2 at Balmoor in the second round.
Russell McLean had the Buchan team ahead before Ciaren Chalmers levelled for the visitors from Fife.
In the second period Rory McAllister had a goal chalked off and hit the woodwork before finding the net and Derek Lyle bagged the third.
Matthew Gay got a consolation for Kelty, who will have Barry Ferguson starting work as their new manager this week.
McInally was pleased to get through after a disappointing first half.
He said: “In the first half we weren’t good enough and it was like a cup final for them so they were fired up.
“We got as good a start as you could hope for when Russell got the first early on.
“But they were never discouraged, they kept pressing us and we weren’t doing well enough.
“They scored from a free-kick down at the corner flag.
“In the second half we played quite well. Rory had a goal disallowed and he hit the woodwork.
“Generally it was comfortable because by the time they scored their second goal, the game was finishing.
“The most disappointing thing was we lost two goals from set-pieces, they didn’t have a shot from open play.
“As poor as we were in the first half we defended well from open play.
“The pleasing thing in the second half was that the squad showed its strength.
“Ross Kavanagh went on and was different class and Derek Lyle went on, made the second goal and scored the third goal.”