The Rocks slumped to defeat at the home of title rivals Whitehawk and had a man sent off for the second game running.
The 3-0 loss was only their second league reverse of the season but it leaves Jamie Howell and Darin Killpartrick’s men just two points clear of their hosts and third-placed Folkestone.
But they face losing James Crane to a three-game ban for his second-half red card - the same length of suspension Jon Marzetti starts next week - and have a new injury worry over central defender Ben Andrews, who went off early with what appeared to be a new knee problem.
The Whitehawk team included Craig Richards, Mark Knee, Stuart Tuck, Sam Gargan and James Fraser – all players that have performed in the green and white over the past decade.
The Rocks started well enough: Crane hit the ball on the rise to cross for Jason Prior, playing probably his final game for the Rocks before he departs for a Newcastle trial, near the back post. But his header was just saved by Winterton in goal.
Moments later, a freekick by Paul Armstrong for the hosts came to nothing as the referee spotted pushing in the box.
Andrews clashed with Keehan in a strong but fair tackle and went to ground clutching his knee. After treatment and his replacement by Chris Breach, it was revealed he had damaged ligaments in his knee and calf. He is due to have an operation on January 17 on a previous and similar injury to the other leg.
Crane did well again on 11 minutes. He set up Terry Dodd, but the striker perhaps should have done better with his shot, firing his attempt wide.
Prior poked a ball through to Dan Beck, who sent his shot the wrong side of the post with only the goalkeeper to beat.
On 18 minutes Fraser almost got in on goal but Craig Stoner managed to dash out to gather at the player’s feet.
Four minutes later Ben Johnson tried to slip the ball in for Kane Wills but instead won a corner. Johnson took the kick from the right and Prior rose highest but headed over.
A short corner lead to Johnson floating across the edge of the box with a spirited run before firing a shot with his left foot. Unfortunately it bounced wide.
A long throw by Richards found Fraser in the box but, under pressure from the Rocks defence, he couldn’t direct his header goalwards.
Kyle Vassell set up Fraser again with a cross. Unmarked, the ex-Rock headed towards goal but Stoner saved well with his legs.
El-Abd was shown a yellow card on 30 minutes after arguing with the referee about two tackles in quick succession.
Jon Marzetti was booked for similar offences five minutes later and Vassell’s free-kick from the incident fell straight on to the head of Richards, who diverted the ball into the bottom corner. It was the first time the Rocks had trailed in a game since the visit to Folkestone on November 12.
The Rocks tried to reply but Johnson’s chipped free-kick into the area was headed over by Stuart Axten.
On 41 minutes Whitehawk went 2-0 up. Vassell’s cross found Fraser in the box. He had his back to goal but managed to volley it over his head and the shot looped up over Stoner and into the net.
Marzetti was replaced by Steve Harper at half-time, seemingly a precaution for his pending suspension and with the yellow card he had received already in this game.
The hosts had the first opportunity of the half. Stoner had to dive down quickly to deny Vassell, then minutes later Fraser was set up by Gargan before shooting from long distance, but the ball flew wide.
Two attempts came and went for the Rocks. Wills’ cross was heading for Axten but was cut out by Winterton, then Prior shot wide from inside the box after a corner.
The third goal came on 54 minutes. Vassell, who was the hosts’ main threat throughout, received a cut-back pass from Fraser inside the box to slot home with the help of a slight deflection.
With 30 minutes left, Prior went down in the box but the appeals were ignored before the ball rolled harmlessly off for a goal-kick – ending a rare second-half attack.
Gargan was booked on 64 minutes after sliding in late on Wills in the middle of the field.
On 70 minutes Bognor seemed to go to sleep in defence as Vassell was allowed to speed through to shoot from the edge of the box, but his attempt flew over the bar.
They failed to clear their lines again two minutes later. Vassell had only Stoner to beat but yet again his shot was inaccurate.
On 76 minutes Crane was given a straight red card after sliding in on a player. He appeared to get the ball but, according to the referee, his feet were high in the incident.
Godfrey played a neat one-two with Vassell before running into the box and flashing his attempt across the face of goal. On the counter-attack, sub Callum Saunders sped through but his chipped attempt was well wide.
Godfrey was given space again in the Rocks half, allowing him to shoot rom 30 yards, but it whizzed over the bar.
The Rocks failed many times in the final third and the closest they came towards the end was when Saunders tried to play in Prior with a low cross, only for the defence to clear the danger.
The management would have been disappointed with the display - especially in the second half - and will hope for better at home to Ramsgate this Saturday.
ROCKS: Stoner, Marzetti (Harper HT), Wollers (Saunders 59), Crane, Axten, Andrews (Breach 9), Beck, Wills, Prior, Dodd, Johnson. Unused subs: Bond, Boyle.
Get all the reaction to the defeat, plus the latest on Jason Prior’s Newcastle trial, in the Observer - out on Thursday