A hat-trick for Tyler Martin helped Newark Flowserve claim a comprehensive 6-2 success over fellow title-contenders RHP Social.
They inflicted a first league defeat on RHP, who move down to second in the league following a victory for Newark Town on Sunday.
RHP had the early chances and pressure and could have been a few goals ahead but for some crucial blocks and good saves from Andrew Dell.
Shortly before half-time Flowserve took the lead when Martin tackled Danny Purves and broke forward quickly. He played it to former RHP player Daryl Price, who shot from 20 yards under the body of keeper Nathan Burrows.
The second-half started brightly for Flowserve and they added a second through Ashley Reed, who cut inside from the right and fired low into the corner.
RHP started to push more players up in attack, and it backfired with Price scoring his second after rounding Burrows and firing into the empty net.
Liam Moran pulled one back for RHP, rounding the keeper before tapping in.
Martin soon took over the scoring and notched his first with a chip from 25 yards out, before slotting into the corner after being played through one-on-one.
James Lloyd scored a second for RHP, but Martin completed his hat-trick with a header after Price chipped the ball into the box.
Newark Town moved top with a 5-1 success over Wheatsheaf United in what was effectively a dress rehearsal for the Willie Hall Cup final.
Town broke the deadlock in the first minute when Louis Cree took advantage of confusion between the keeper and a defender and lobbed the ball into the net.
The second came from a corner, Luke Parsons heading the ball into the path of Simon Greenfield who could not miss from close range.
Town added a third after half-time when Leigh Cooksey found the roof of the net from a tight angle.
Jimmy Rusby bundled in a fourth from Stefan Bilyk’s cross before Tom Perkins rounded off the scoring for Newark with a half-volley from 25 yards.
A late consolation was added for Wheatsheaf through Max Danby, who forced the ball home after a scrap in the area.
Newark Town lead both RHP Social and Newark Flowserve on goal difference, with games in hand over both teams.
Mid-table East Bridgford Rangers enjoyed a comfortable 4-0 success over Collingham.
Rangers were 3-0 up at the break, and were the dominant side throughout as they consolidated their seventh-placed position.
Chris Barnes scored twice, while Liam Brewer and Bassey Okon also got on the scoresheet.
Barkestone-le-Vale came from behind to earn a 5-3 success over Rutland Arms Rovers.
Rutland led 1-0 at the break, but three goals late in the final 15 minutes took the game away from them.
Robert Lakin scored twice for Barkestone, with Sam Garner and Chris Tonge also getting in on the action late on.
They had also earlier replied through an own goal.
Rutland’s scorers were Joe Fearon, Leighton Nicholson and Craig Self.