The Rocks got their new Ryman premier campaign off to a disappointing start as newly-promoted Grays made them pay for missing so many chances in the first half.
Stuart Axten was back in the heart of defence after recovering from an ankle injury while Dan Kempson, James Crane and Harvey Whyte were all in the line-up. There were competitive debuts for Craig Robson and Arron Hopkinson.
A lively start saw Whyte try to play in Hopkinson on the right but the pass was just too much and the defence cleared.
Jeff Hammond got through the Rocks defence on four minutes. His cross towards Jack West was cleared by a glancing header from Crane.
Kane Wills’ corner from the left fell to Robson, who headed at goal. It was inadvertently blocked by Terry Dodd.
Hammond latched onto a Lee Flynn pass down the right. After squirming past Robson he hit a low shot well wide.
Kempson’s pass found Dodd on the run but the striker’s left-footed shot whizzed low and wide past the post.
On 14 minutes Wills outpaced the defence and crossed for Dodd. His shot rolled wide.
A free kick on the right for Grays saw Joho Carlos’ low left-footed cross bounce through the crowded area and off for a goal kick. Carlos hit an attempt over the bar seconds later.
Wills’ corner on 20 minutes found Axten, whose header was blocked before the ball fell to Whyte, who smashed a shot well wide.
The visitors took the lead on 21 minutes. Carlos was put through and slid a low shot beyond Mark Zawadski.
Whyte’s curling shot was only just beyond the top corner on 28 minutes and Whyte went close again after he ran square across defence on 31 minutes.
Craig Pope’s right sided cross found West in the area but he spun his header high and wide - before Alex Cruikshank’s attempt at a cross from the left flew out of touch.
The visitors made changes for the second half. On came Junior Baker for Kirby, and Apron Ramos-Gonzales came on for Small.
Ramos-Gonzales was booked for blocking the goalkeeper after Bognor were awarded a free-kick in their own area.
Doug Tuck played in Hopkinson down the right but the winger’s cross .
On 55 minutes Dodd fired a shot straight at goal from a tight angle and it needed Kamurasi to push the ball away with a good save.
Kempson stopped Hammond getting in through on goal before being replaced by Ollie Pearce on 61 minutes.
Pearce ran with the ball before chipping the ball forward to Dodd but his attempt was deflected away by a defender.
Grays extended their lead against the run of play. West was let through the defence too easily, with Bognor defenders failing to get a tackle in before he slid a low shot into the net from just inside the box on 64 minutes.
Tuck was brought to ground with a tackle as he ran towards the box, but Wills’ free-kick was cleared. Wills hit a shot well over the bar from 30 yards.
Grays went close again after a free-kick found Hammond but the striker slid his shot narrowly wide.
Whyte was booked and a 78th-minute free-kick saw Ramos-Gonzales’ effort bounce past everyone to put the game beyond reach for Bognor.
Daryl Wollers came on for Axten on 77 minutes and Whyte was replaced by Dan Sackman on 82.
The Rocks failed to make any real attempts on goal in the last ten minutes - ending a miserable first home game of the season at Nyewood Lane.
They’ll hope for better when they go to Wealdstone on Monday night.
Rocks: Zawadski, Marzetti, Tuck, Crane, Axten (Wollers 77), Robson, Hopkinson, Wills (c), Dodd, Whyte (Sackman 83), Kempson (Pearce 61)
Unused subs: Tribe.