Bognor’s run of nine games and more than two months without defeat was ended by a late header at Hendon.
Jamie Howell’s side wouldn’t have been unhappy to come away with a point but new keeper Grant Smith was left with no reward for another fine performance when Leon Smith headed home from an 87th-minute header.
The Rocks remain sixth in the Ryman premier - just outside the play-off zone - and will look to get back to winning ways at Enfield on Saturday.
Bognor started well playing up the slope and Dan Thompson forced a first-minute corner that came to nothing. Thompson was proving a handful and had a shot held by home keeper Joe McDonnell.
Hendon right-back Chris Seeby created a couple of chances and Dave Diedhiou twice went close - seeing a shot saved by Smith before hitting one wide from a handy position.
Kane Wills went on a superb 60-yard run for Bognor but was forced wide and saw his shot saved, while at the other end Michael Bryan beat Smith with a lovely curling shot that was just wide.
Bryan set up Michael Murray for a chance that was thwarted by Craig Robson’s intervention, while Ben Godfrey’s claims for a penalty after a tackle in the box.
Diedhiou had a fierce shot palmed over by Smith and Casey McClaren headed wide with the keeper beaten.
There was new injury woe for Bognor five minutes before the break when on-loan Pompey midfielder hobbled off - it was later revealed he had broken a toe.
Just before the break, Anthony Thomas wasted a great opportunity to open the scoring for Hendon when he blazed over after being put clear by Jack Bennett.
Bognor started the second half well and McDonnell saved at Thompson’s feet.
James Crane cleared one effort off the line and Murray wasted another chance, and with ten minutes to go Dan Kempson produced one of the tackles of the season after Thomas rounded Smith and seemed certain to score.
Sub Jose Figura’s 25-yard effort was well saved by Smith with three minutes left - but from the corner, Leon Smith headed in from a few yards out.
Crane and Stuart Axten, back after an injury lay-off, both tried to fashion a late equaliser but it wasn’t to be and Bognor came home reflecting on their first defeat since mid-December.
ROCKS: Smith, Hinshelwood, Crane, Tuck, Axten, Robson, Awford (Kempson 40), Wills, Godfrey (Whyte 65), Pearce, Thompson (Dodd 55). Subs not used: Sackman, Wollers.