A second-half winner from Jesse Starkey saw Lewes fall to a 2-1 defeat against local rivals Worthing in front of a sell-out crowd at the Pan, reports Tom Harper.
Tony Russell made two changes to the side that drew 0-0 at Corinthian Casuals in their previous game, with Casey Pettit and Ollie Tanner replacing Matt Weaire and Razz Coleman De-Graft in the starting line-up.
Worthing made a bright start and could have taken the lead early on, with Lewis Carey making a smart save to keep out an Aarran Racine header.
Carey remained the busier of the two goalkeepers as the half progressed, denying Callum Kealy and then saving a powerful Ollie Pearce effort.
The visitors took the lead their first-half performance had arguably deserved on 32 minutes, as Kealy flicked a Jasper Pattenden cross from the right past Carey and into the back of the net.
Lewes responded well though, and levelled the scores just six minutes later, an Ollie Tanner cross from the left being deflected into his own net by Racine.
Worthing should have regained their lead just before the break, but saw Pearce shoot wide with only Carey to beat after being played through on goal by Reece Myles-Meekums.
Lewes started the second half on the front-foot, with Rhys Murrell-Williamson exchanging passes with Taylor Maloney before seeing his strike from a tight angle saved by Harrison Male at his near post.
Worthing began to regain control after a bright start from the Rooks, and Maloney was forced into a smart block to keep out a goal-bound effort from a quickly taken corner as the visitors looked to go back in front.
Long periods of the remainder of the half passed without incident, with both sides defending well and ensuring that Carey and Male remained relatively untroubled.
The visitors started to turn the screw again heading into the final 20 minutes though, and saw Jesse Starkey shoot just wide from the edge of the area after a deflected shot dropped into his path.
This proved to be a sighter for Starkey, as he sent his next effort, a half-volley from the edge of the area, past Carey and into the roof of the net to put Worthing back in front on 77 minutes, sending the travelling supporters behind the goal into raptures.
Lewes fought for a route back into the game in the closing stages, but were unable to really stretch the Worthing defence or force Male into any action of note, with the visitors holding on to record a vital win in their push for the title.
You can watch highlights of the game, thanks to Your Instant Replay, here.
You can read the progcast here
More photos from James Boyes can be found here.
Lewes will hope to put this result behind them when they travel to Leatherhead on Tuesday, kick-off at 7.45pm.
Lewes: Carey, Spencer, Carlse, Salmon, Pettit, Klass, Maloney (Phipp 82), Pritchard (McLeod 87), Murrell-Williamson (Dalling 72), Tanner, Taylor.
Unused Subs: Yao, Nelson.
Booked: Carlse, Maloney.
Worthing: Male, Colbran, Tutt, Barker (Armstrong 28), Racine, Pearce, Starkey, Beresford, Kealy (Seager 90), Myles-Meekums (Golding 68), Pattenden.
Unused Subs: Cocoorrachio, Robinson.
Booked: Racine, Pearce.