Bognor fell to their first loss of their pre-season preparations as Wessex League side Hordean's Connor Duffin netted two to secure a 3-0 win.
Cian Tilley deserved a start against Michael Birmingham's Horndean and Jack Parkinson was on the bench again after he was the matchwinner coming off the bench against Brighton last Tuesday.
Early on the Deans' Harry Jackson had a chance but was held off by Tommy Block. Jackson then scuffed a chance well over the bar and had a low shot blocked.
Jimmy Muitt's incisive pass towards Cian Tilley was too much for the striker and goalkeeper Kieron McGhee belted it away. A corner fell to Harvey Whyte but he skied his chance.
Horndean's Fuzz Kanjanda caused problems on the left but the Deans couldn’t capitalise. Ex-Rock Dan Sackman headed wide narrowly from a corner.
Patient play from Bognor saw Calvin Davies chip the ball towards Doug Tuck but the keeper got there first. Jimmy Muitt was brought down just outside the box on 23 minutes but Davies's direct free-kick flashed wide.
Zac Glasspool was sent through one on one with trialist Rocks keeper Giodano Zabotti, who raced out of his area to divert it away from the forward just in time.
The Rocks saw a series of half-chances go awry before Zabotti was called into action to deny two attempts from inside the box as Zac Glasspool and Jack Maloney were denied.
Muitt's corner fell to Marley Ridge and then Whyte but both saw attempts kept out by desperate defenders.Then Muitt let fly with a 25-yarder which clipped the top of the bar.
There were wholesale changes as nine changes were made by Bognor for the second half with only Zabotti and Keaton Wood staying on. Among the subs were Parkinson, Tommy Scutt and Amari Wood along with Jamie Carroll, who featured against Brighton. Archie Thorpe, Greg Phillips, Joe Bennett and Vincent Follea were also involved. Liam Brady came on later in the half.
Kanjanda was exploiting the Rocks young defence with quick runs down the left - before Parkinson forced a decent save from the Deans goalkeeper on 55 minutes.
Liam Kimber, Luke Head, George Thomas and Louis Edwards came on for Horndean, followed by Miles Everitt.
Before their fifth change, Glasspool put the Deans in front - he received the ball along the deck from the right and after pouncing on a deflection off Wood he slotted it neatly into the bottom corner.
Duffin scored Horndean’s second after peeling away from his marker before slotting the ball low into the bottom left corner.
For Bognor, Brady's strike was high and wide on 79 minutes. Then it got worse for Bognor's experimental team as Benny Reid made the byline before cutting the ball inside the box to Duffin, who turned before shooting low in the bottom right corner to go three up.
Tommy Scutt's low shot from long distance was easily saved with only a minute left to play.
Rocks: Zabotti, Whyte (c), Sparks, Tuck, Wood, Rolf, Ridge, Block, Tilley, Muitt, Davies. Subs: Scutt, A Wood, Parkinson, Brady, Carroll, Thorpe, Phillips, Bennett, Follea
Horndean: McGhee, Reid, Kanjanda, Hookey, Sackman, Lee, Maloney, Howes (c), Glasspool, Liss, Jackson. Subs: Head, Llewellyn, Thomas, Edwards, Everitt, Kimber.
See a report from Rocks v Pompey XI on this website on Tuesday night and get all the latest from Nyewood Lane in the Observer every Thursday.