Aron Burton bagged another double, while Robert Hodgkins and Josh Blakey were also on target as Old Boys made it eight games unbeaten in all competitions and moved within a point of the top three.
Their final league game of the season comes on Saturday when they host Tetney Rovers at London Road (ko 2.15pm).
Sutton Rovers were stunned as they lost their top-of-the-table clash 9-1 at home to Division Two leaders Susie Star.
Jake Brownson got the consolation for second-placed Rovers.
And there were also goals aplenty at Louth Old Boys Reds who went down 7-6 at home to third-placed Manby.
Jordan Tebbs hit one of three hat-tricks in the match, while James Harness, Oliver Thomas and Bailey Wright were also on target.
And in Division Three, Louth Old Boys Vets came away from bottom side East Coast Blades with a 3-2 win thanks to goals from Phil Allen, Andy Smith and Graham West.