Long Eaton arrived at Willingham Road as leaders on the back of a three-match unbeaten start, but injuries had ravaged their side and an under-strength XV took to the field.
The Red and Greens found themselves in a similar position with five enforced changes from their win at Lincoln, but as the game wore on it was Rasen who acquitted themselves the better.
The hosts started strongly as the forwards took the game to Long Eaton, establishing the platform that would underpin the victory.
After several phases Rasen edged their way closer to the line until number eight Jake Pryer crashed over in the fifth minute.
Long Eaton came back and forced Rasen deep into their own 22, but the burgeoning forward supremacy saw the Red and Green eight take the scrum against the head to play their way out of danger.
The visitors’ strength lay in their young backline, and full-back Adam Castle used his pace and quick feet to elude the narrow defence and level the scores.
Rasen’s forward control paid dividends when they won a penalty and drilled the ball into touch.
A successful catch and drive allowed skipper Ben Chamberlin to restore the lead, but five minutes later Kyran Powell’s penalty reduced the deficit to 10-8 at half-time.
Long Eaton went ahead almost straight from the restart when a swift move found winger Oliver Davidson to scoot down the touchline before popping the ball back inside for supporting flanker Adrian Else to dot down.
Things took another turn for the worse for Rasen three minutes later when Jake McLoughlin was sin-binned for a no-arms tackle.
But despite the numerical disadvantage, Rasen defied the norm to score two quick tries before being restored to the full 15.
More forward pressure eked out another penalty as the Red and Greens drove forward from the lineout before Nick Harvey cut in from the wing to dive over.
Three minutes later, Long Eaton conceded another penalty in their own 22.
Scrum-half Mike Starling quickly tapped to scamper in under the posts to leave Will Pridgeon with a simple kick to break his duck.
Another promising Long Eaton attack broke down deep in Rasen territory with the hosts breaking out and Josh White eventually bundled into touch close to the visitors’ line.
This should have provided Long Eaton with some respite, but a poor throw fell straight to substitute Dave Starling who gratefully dived over the line, having only been on the field for a minute.
Both sides continued to attack and defend in equal measure, with neither finding a way through until five minutes before the end.
A Rasen attack was completed when Marius Berger joined the line from full-back to outpace the defence for the final score of the match.
Long Eaton had no answer to the Rasen eight in the set-piece and their attacking edge was blunted by well-organised defence.
Five tries was a good return, but better decision-making could perhaps have yielded more in what was a very satisfying afternoon’s work.
On Saturday, Rasen travel to Loughborough who recorded their first win of the season last weekend (3pm kick-off).
Rasen and Louth: Ashton (Howard), Alldridge, Southwell, Chamberlin, Crowe, J. Norton, Grant, Pryer, M. Starling, White, Harvey, McLoughlin (D. Starling), Medd, Pridgeon, Berger.
* The Second XV continued their unbeaten run to lie second in the Yorkshire Eastern Merit table with a 26–17 win at Pocklington.