It was a first taste of victory for new manager Gavin Hurren, as first half goals from Mark Smith and Devante Reittie proved enough to secure only their seventh win of the season to move them within a point of Carlton and Stocksbridge above them.
Perhaps even more encouraging is that they managed to do it with 10 men for 79 minutes, after Dexter Morris-Clarke was sent off early on for a foul on Jack Keeble.
Although Danny Setchell reduced arrears before half time, Gresley held on for a vital three points.
That result leaves Carlton looking over their shoulders after they were battered 6-2 at home to high-flying Pontefract Collieries.
Tyler Blake had given the strugglers a third minute lead, but by 33 minutes, they were 4-1 down, with goals from Jack Greenhough (2), Gavin Rothery and Chris Jackson.
A rout looked certain when Vaughan Redford added a penalty on the half, and though Ben Hutchinson pulled one back, Nick Guest rounded things off late on to consolidate second place in the table.
Ossett United moved in to the play-off places with a 3-1 win at Frickley Athletic.
Adam Priestley gave them an early lead, though Ousman Cham equalised on his debut for the hosts.
A Sam Liversidge own goal save Ossett a half time advantage, but they had to wait until the 88th minute to be sure of the points, Aidan Chippendale scoring the third.
Brighouse Town were 4-0 winners away at Lincoln United. Zephaniah Thomas gave them a 1-0 half time lead, with the rest of the goals coming in the final quarter.
Aaron Martin, Iwan Heeley and Thomas Robinson were the scorers as Brighouse remain third.
Tadcaster Albion ended the weekend with severe worries at their ground due to flooding, but they did at least manage to get Saturday’s game at home to Spalding United over and done with before tragedy struck.
Aiden Savory scored a brace to lead Taddy to a 3-0 win, Joe Lumsden scoring the other goal, as they remain in the play-off picture.
Sheffield were the main losers of the weekend, being held 2-2 to a draw at Stamford which saw them slip out of the top five.
Andrew Gascoigne’s penalty two minutes in to the second half put them in front, before Joe Burgess scored two goals in three minutes to turn it around for the hosts.
Luke Rawson’s equaliser rescued a point for Sheffield, who are level on points with Ossett but have an inferior goal difference.
The only other game that survived the weather saw Loughborough Dynamo beat Belper Town 2-0, a result that dents the Nailers ever decreasing play-off hopes.
Karl Demidh’s goal on the stroke of half time was added to by Ryan Robbins on 72 minutes for Dynamo, who are nine points off the top five.