Bognor are out of the Bostik premier play-off zone after a disappointing 3-2 loss at home to promotion rivals Tonbridge Angels.
They were a goal down in 21 seconds but fought back to lead 2-1 through goals by Brad Lethbridge and Jimmy Muitt. But Tonbridge levelled before halfg-time and converted a second-half penalty to claim the spoils.
The result leaves the Rocks down to eighth in the table and now they must lift themselves for a visit to third-placed Merstham on Wednesday.
Bognor welcomed back Pompey forwards Lethbridge and Dan Smith after the Rocks did a fresh deal with their parent club to loan them for the rest of the season. They started up front alongside top scorer Muitt, with Doug Tuck, Richard Gilot and Harvey Whyte in midfield.
Tonbridge arrived at the Lane in good form having won their past three league games, and had a former Rocks forward Chinedu McKenzie in their frontline.
Bognor have also been in decent form of late, taking 13 points from their past six league games to sit fifth in the table as the game kicked off.
But the Rocks got off to a terrible start when they conceded a goal 21 seconds into the game. Tonbridge attacked down the left and when left-back Jack Parter crossed, it flew off the top of Ed Sanders' head, over Dan Lincoln and into the far corner.
A late tackle on Gilot by Tom Parkinson might have brought an early card – as might some early time-wasting by McKenzie that riled the home fans.
The first Rocks effort at goal came from Lethbridge on nine minutes when he picked up a loose ball in midfield and surged forward, but his shot drifted wide.
Bognor looked nervous, something shown when Lethbridge gave possession away 30 yards from his goal to allow D'Sean Theobolds a low shot that Lincoln held.
The Rocks came to life and levelled on 15 minutes. Tuck and Whyte combined in midfield to get the ball out wide on the left to Lethbridge. He ran at a defender, cut inside and unleashed a fierce shot that was too good for keeper Jonathan Henley and flew in.
Two minutes later the turnaround was complete as Tuck did well to feed Muitt, who dribbled into the box, took a touch to wrongfoot his marker and fired low across Henley and in.
Parter put a couple of dangerous balls into the Bognor box that the defence dealt with midway through the half. JoeTomlinson swung a high ball to the far post where Sanders was close to heading in.
It might have been 3-1 on 26 minutes but Whyte spun a header just over when Muitt curled a nice ball into the six-yard box. But just as Bognor looked to be on top, it was 2-2 on 28 minutes as Joe Turner's inswinging cross was nodded in by Alex Read under pressure from his namesake Harvey Read.
In a promising Rocks attack Lethbridge made good progress down the left and his cross looked set to fall for Whyte but a defender got a head on it.
Then it was almost 3-2 at the other end as James Folkes' cross was only just scrambled clear by Sanders as Turner lurked. Parter was booked for a crude foul on Muitt as he advanced down the right in first half injury time.
Tommy Scutt replaced Sanders at the start of the second half.
Angels were back in the lead ten minutes into the second period when they were awarded a very soft penalty for an innocuous challenge on Sonny Miles by Tomlinson. Lincoln guessed correctly which way Turner was going to put the spot-kick and got both hands to it, but it went in.
Tonbridge smelled blood and went close to a fourth on a couple of occasions, while Bognor were again struggling to find their fluency.
The play wasn't flowing at all, with niggly fouls causing hold-ups and the referee not instilling much confidence with his handling of things.
Muitt was played in on the right and his cross found Smith, whose ambitious back-heel attempt went wide. A neat move down the right opened up space for Tuck to shoot from 15 yards but it was superbly saved by Henley.
Whyte cut a free-kick back to Tomlinson whose low shot was blocked by a defender. Parkinson tested Lincoln with a thumping volley from 25 yards as the final quarter-hour began.
Tomlinson ran in on goal and drew a desperate save out of Henley, then Whyte's curling 20-yarder brought an excellent tip away from the keeper. From the corner Henley saved Whyte's header low down.
Young midfielder Liam Brady made his Bognor debut on 84 minutes, replacing Field. He immediately went into the frontline, with Gilot dropping back into defence. Brady, who is due to represent England Colleges in a tournament in Italy this month, showed some useful touches in the short time he was on.
Tomlinson tested Henley again with a fierce shot from 22 yards. At the other McKenzie headed an 87th-minute corner over the bar in a let-off for Bognor.
The Rocks were doing plenty of attacking in the final few minutes but nothing was falling for them. Even sending Lincoln up for a couple of corners didn't bring an equaliser and the Rocks were left to reflect on a pointless afternoon.
Rocks: Lincoln, Sanders, Tomlinson, Tuck, Field, Read, Whyte, Gilot, Smith, Muitt, Lethbridge. Subs: Scutt, Heath, Osborne, Brady.
Tonbridge: Henley, Folkes, Parter, Theobolds, Miles, Lee, Ramadan, Parkinson, Read, McKenzie, Turner. Subs: Stone, Bere, Small, Smith.
Ref: Tristan Greaves