A Fin Sinclair-Smith double, either side of Sol Solomon's 12th minute goal, proved enough to see the Mariners secure all three points with a 3-2 win, despite a late goal from Radcliffe midfielder Josh Hancock setting up a nervy last few minutes at the Marine Travel Arena.
The Boro's slip-up allowed Warrington Rylands to close the gap at the top to four points after their 1-0 win over FC United of Manchester.
Scott Bakkor's goal early in the second half was enough to see the in-form Blues make it 10 games unbeaten and record their fifth successive win in all competitions.
First half goals from Jason Gilchrist and James Hardy helped Ashton United to a 2-1 victory at home to Bradford Park Avenue, as the Robins made it three wins in a row.
Macclesfield occupy the final play-off place, despite being held to a 1-1 draw at Ilkeston Town.
Kane Drummond put the Silkmen ahead on 71 minutes, only for in-form Tigers forward Jamie Walker to level matters with his 10th goal of the season.
Elsewhere, Liam Hughes was on target again for Worksop Town as they beat Matlock Town 2-0, while a Jacob Gratton double helped Whitby Town to a 4-2 win at home to Marske United.
Workington picked up three points at home to Lancaster City, leapfrogging the Dolly Blues in the table, and Sam Hodgson rescued a point at the death for Morpeth Town as they drew 1-1 with Guiseley.
At the Skuna Stadium, last season's beaten play-off finalists Bamber Bridge staged a late fightback to beat Atherton Collieries 2-1.
Colls had led three minutes into the contest through Nathan Caine, only for Macauley Wilson to level from the penalty spot 13 minutes from time before Harry Scarborough snatched all three points in second half stoppage time.
Finally, Hyde United beat Stafford Rangers 2-1 to climb up to 13th in the league.
Goals from Jimiel Chikukwa and Jack Redshaw mean the Tigers have now won their last three matches in league and cup.
Results - Tuesday 26 September
Ashton United 2-1 Bradford Park Avenue
Atherton Collieries 1-2 Bamber Bridge
Ilkeston Town 1-1 Macclesfield
Marine 3-2 Radcliffe
Morpeth Town 1-1 Guiseley
Stafford Rangers 1-2 Hyde United
Warrington Rylands 1-0 FC United of Manchester
Whitby Town 4-2 Marske United
Workington 2-1 Lancaster
Worksop Town 2-0 Matlock Town
Photo credit: Warrington Rylands
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