A host of first teamers were missing for Mablethorpe, so reserves Anthony Parnell, Danny Bishop, Jake Brownson and Marcus Marshall were drafted in.
All had good games and proved they are capable of playing first team football.
The visitors were on the front foot early on with stand-in custodian Adam Brownson, who usually plays outfield, making a great save to deny Jake O’Callaghan.
Joe Mitchell then came close with a long range effort before breaking the deadlock on 19 minutes.
He latched onto a Shaun Topliss through ball and lobbed the out-rushing Brownson to score.
Soon afterwards O’Callaghan was played in by Louie Schofield and he doubled the lead.
Mablethorpe kept going with good efforts from Stuart Parnell and Mitch Whiley.
The hosts began the second half brightly with Parnell forcing Iain Tilmouth into a fine save.
Minutes later Mablethorpe thought they had pulled a goal back.
Alex Carter ran onto Whiley’s through ball and fired in, only to see the flag up for offside.
Parnell then came a whisker away from scoring with a powerful strike deflected off the inside of the left post and onto the right post but somehow stayed out.
Midway through the second period Mitchell had one shot saved by Brownson and he saw another fly narrowly wide.
Schofield was then unlucky to shoot inches wide of the right post.
At the other end the alert Tilmouth made a top draw save to keep out a thunderous Parnell drive.
Late on Brownson palmed Ben Charlesworth-Brown’s attempted cross onto the right post at full stretch.
In the final minute, Horton le Clay notched a third goal when O’Callaghan beat the offside trap and slotted home.
Mablethorpe manager Mick Stubbs had mixed feelings afterwards shortly after the final whistle.
He said: “Firstly, a massive thank you to the lads from our reserves who came in and all played very well.
“It was hard today and we got off to a bad start.
“With players missing there were changes and we took time to settle.
“We played well in the second half and made chances, but we could not put the ball in the net. The final ball needs to be quicker and better.
“If we can find a bit better quality in the final third we can win more games.”
Athletic host Louth Old Boys on Saturday (2pm).
Mablethorpe Athletic (4-5-1): A.Brownson; Thomas, Carter, Bishop, J.Brownson (Williamson 78); M.Marshall, D.Marshall, Sirett (c), Whiley, A.Parnell; S.Parnell (Spybey 63).