The under-16s were denied a cup final appearance as under-14s by the Covid-19 pandemic in 2020 and they made no mistake in their clash with Market Bosworth.
The team, from U7 to U16, have never lost a match in the LRU County Cup throughout their junior rugby journey, a fantastic record kept intact in this final.
It didn't take long for Harborough to show their strength and Docherty opened the scoring with a try in the corner. A similar move soon followed up the opposite flank, with Hepworth scoring and Williams added the extras to make it 12-0.
Bosworth hit back with a penalty but, from then on, Harborough dominated and tries for Smith and a brace for Bradley saw them 27-3 up at half-time.
Harker extended the lead to 32-3 and, after Bosworth pulled a converted try back before Docherty got his second of the day.
Another strong Harker run resulted in a scramble for the loose ball but Hepworth was able to get the important touch to make it 44-10.
Further Harborough pressure then saw Fletcher on hand to score and the final points were scored and converted by Williams with the referee calling time at 58:10.
To cap a great day for Harborough's junior players, the Under-15s also won their final, 39-14 against Hinckley.
Tries from Fergie Hanna and Albert Abel, who was set up by man-of-the-match Sam Byrd, put Harborough 10-0 up and it was 17-0 before half-time when Abel scored again with Charlie Barkworth adding the conversion.
Harborough were in control in the second half and extended their lead when speedster Robert Wardlaw ran half the length of the pitch to touch down.
He scored again soon after, finishing off a wonderful team try after multiple phases with the pack recycling the ball brilliantly.
Hinckley pulled a try back to make it 29-7 but Harborough took the sting out of things when Barkworth knocked over a penalty and Wardlaw then completed a fantastic hat-trick of tries.
Hinckley scored again late on but there was no time for a comeback as Harborough celebrated being crowned county champions.