The Rocks continued their perfect start to the campaign - and ended Whitehawk’s - thanks to a Luke Nightingale penalty early in the second half.
It was a clash between the two favourites for the Ryman one south title but the visitors looked anything but promotion candidates as they slipped to their first defeat.
The Rocks’ fourth win from four - and their first on August bank holiday Monday for seven years - put them second in the table with only Dulwich Hamlet in front of them on goal difference. Worthing, who were also ahead of the Rocks at the start of play, slipped up with a 2-2 draw at Burgess Hill.
The Rocks had to leave hip-injury victim Jason Prior on the bench but could call on Nightingale to replace him alongside Terry Dodd. Jon Marzetti was fit to start despite a calf injury picked up at Hythe.
James Crane escaped an early booking after a crunching challenge on the halfway line and the early exchanges were fairly cagey.
The Rocks had by far the best of the early stages and threatened a number of times in the opening 15 minutes – usually through Ben Johnson’s crosses from the left wing.
One Johnson fell to James Fraser at the far post and when he swung it back in, Dan Beck’s goalward header fell at the feet of Nightingale, who was denied as keeper Chris Winterton blocked his effort.
Johnson swung in another two teasing crosses within the first ten minutes before the Hawks’ first chance fell to Ben Godfrey, but he stumbled over the ball with the goal in his sights.
On 13 minutes Dodd beat his marker to a ball into the area and almost squirmed a shot under Winterton, who managed to grab hold of it.
Whitehawk had the ball in the net on 15 minutes but Sam El-Abd’s header from a free kick was ruled out for offside. It was soon 1-1 in disallowed goals as Dodd dispossessed the keeper on the edge of the box and put the ball in the empty net only to have a foul given against him.
Jerahl Hughes looked a threat for Whitehawk and he twice went close to putting them in front. First he fired into the side netting from only eight yards out after creating an opening for himself, then he was denied by a superb stop by the onrushing Craig Stoner after Jon Marzetti had given the ball away on the Rocks’ right touchline.
The Rocks were getting sloppy – giving the ball away in their own half too often – while the match was becoming niggly and was interrupted regularly by the referee’s whistle, often blow for no obvious reason.
Stoner held Paul Armstrong’s long-range free-kick at the second attempt but the Rocks couldn’t find the rhythm that had earned them wins in their first three matches. Instead it was the top-of-the-table Hawks who looked the more comfortable side.
Fraser tried one from 25 yards five minutes before the break but it was all along the floor and well wide.
When the Rocks did put a cohesive move together, Fraser’s long ball in from the right fell to Johnson beyond the far post but his ball back into the six-yard box evaded everyone.
Skipper for the day Dan Beck was booked for dissent on 44 minutes as the Rocks’ frustration grew over a succession of decisions given against them. There were ironic cheers from the home crowd when the latest Hawks free-kick ended in a visiting player being blown against for handball.
Whitehawk brought on Karly Akehurst for Godfrey for the second half.
The Rocks got the breakthrough in the fourth minute of the half. Fraser’s surge into the box down the right was halted by a trip by ex-Rock Mark Knee and Nightingale sent Winterton the wrong way from the spot. It was the first goal the Hawks had conceded this season.
It should have been two on 56 minutes when Johnson’s pinpoint cross found Dodd unmarked at the far post. But the keeper got a hand to his header and it was scrambled clear before Nightingale could put away the loose ball.
The match was becoming increasingly physical and the referee didn’t always seem to be in control.
Whitehawk made a second change on the hour as Fraser Logan replaced Ryan Thompson.
Ex-Rocks striker Sam Gargan gave his old team a scare when his header back across Stoner shaved the top of the bar as he met Josh Jones’ free-kick.
Dodd had another goal disallowed after finishing from the corner of the area thanks to Crane’s through-ball, although this time he had been ruled offside well before putting the ball away.
Whitehawk sub Akehurst almost scored a spectacular own goal when he overhit a high curling backpass to Winterton that the keeper had to belt out for a corner, which he then claimed.
Nightingale was booked for an innocuous-looking challenge – and was then immediately subbed for Prior to make a surprise appearance.
The visitors also made a change, Marc Pullan coming on for Jones.
Tim Bond suffered a cut to the side of his head in an aerial challenge and had to come off for treatment and a change of shirt. He came back on three minutes later with a bandaged head.
The Hawks still carried a threat and Gargan had two bites at the cherry after running into the box when he pounced on a half-cleared long ball with 15 minutes left.
There was another scare at the back when Gargan got to a high hanging ball before Stoner could punch clear but his effort bounced wide.
Hawks right-back Craig Richards was booked for halting Crane’s break down the left with a crude challenge.
The officials indicated two minutes of stoppage time. But that wasn’t enough for Whitehawk to threaten an equaliser.
Next up the Rocks turn their attentions to the FA Cup - they host Camberley in the preliminary round this Saturday.
Before then the new Rocks youth team entertain Burgess Hill at the Lane in their inaugural fixture in the Ryman Youth League. Admission is just £3 or adults, £1 for others.
Rocks: Stoner, Crane, Marzetti, Fraser, Axten, Bond, Beck, Wills, Nightingale, Dodd, Johnson. Subs: Prior, Ide, Castles, Breach, Whitehead.
Whitehawk: Winterton, Richards, Knee, Armstrong, El-Abd, Keehan, Hughes, Thompson, Gargan, Godfrey, Jones. Subs: Akehurst, Saunders, Logan, Harding, Pullan.
Ref: B Furneaux (Ruislip).