The result moves Bognor up to eighth in the table ahead of Tuesday night's visit to Horsham.
Harvey Whyte started on the bench for the Rocks with James Crane moving back into the starting line-up. Jake Flannigan retained his place in the side with Nathan Odokonyero among the subs.
Daniel Bassett did well to work his way down the left early on for the visitors. He cut inside on his own before shooting low and forcing Amadou Tangara into an early save. Ezechukwu Ebuzone went straight into the book after showing his studs in a strong foul on Crane after only 6 minutes.
Lewis White sped down the left but a deflection off a Bognor defender rebounded off the attacker and out for a goal kick. Ashton Leigh did well to get into the area but his cross towards Kayne Diedrick-Roberts was shut down. Then a short corner bounced back inside to Flannigan who hit it at goal and forced a good save from Lloyd Thomas - and then Jordy Mongoy was blocked on the rebound on 12 minutes.
Jalen Jones was highest in the air from Jordan Cheadle’s in-swinging corner but couldn’t direct it properly. Then Tommy Bradford cut inside but his shot at the near post was bravely blocked by a number of Bognor defenders. Crane fouled Bobby Price near the touchline but Cheadle's curling high ball in was headed away.
Leigh did well to run onto Crane's pass before crossing low into the box but Thomas got there first before Mongoy. Tangara had to pull out a fingertip save to push Cheadle's curling direct freekick around the corner of the goal on 22 minutes. Bradford drove in another cross from the right with his left foot but Luke Read was offside. Diedrick-Roberts did well to drive the ball across the face of goal. But Leigh wasn’t quite in the right position.
Mongoy turned with the ball before placing a through ball to Leigh before he sped on and shooting along the deck and agonisingly wide of the right post. Tangara did fantastically well to stop White as he beat Joe Cook to the ball before the goalkeeper bravely closed the player down at the edge of his penalty area.
The Rocks went ahead on 33 minutes. Crane linked up with Leigh before he won a corner on the left. Leigh drove the ball in from the corner straight on to the left foot of Robson who hit it first time on the half volley with the inside of his boot high into the top left corner, a fine strike from the defender.
Mongoy laid the ball off for Leigh who ran in but his pass inside was hacked clear by Ebuzone. Leigh's resulting corner was met by Robson again in the air but he headed it off the defender and out. HT 1-0
Bognor had to defend in the early stages of the second half. Ebuzoene did well to receive the ball, turned and then smashed it well over the bar with his left foot. Bobby Price swirled in another cross but it was headed out by Cook. But the long throw bounced out to White who hit a rather feeble shot from outside the box into Tangara's arms. Leigh took a lofted pass but he was offside and his flicked effort went over the bar anyway.
Joe Dandy clashed in the air with Harry Ottaway and the referee stopped play as he received treatment. Tangara just about cleared his lines when he lost control of a pass back in a nervy moment for Bognor. Leigh's corner was too much for Cook, then Ethan Robb misguided a cross.
Cheadle did well to get a shot away with his left foot but it flew wide of the right post. Substitute, Daniel Hector combined with White who made a small run across the defence before belting it high over the bar. Gavin McCallum replaced Leigh on 70 minutes for Bognor. Cheadle’s free-kick curled over the defensive wall and with Tangara diving to his left the ball rattled off the right post and away.
Another Cheadle cross from the left found Ottaway in the box but he didn’t get enough on his header and it was cleared. Tangara flapped at a Cheadle corner from the left and the follow up cross was poor and easily dealt with. Read went into the book for a late challenge on Diedrick-Roberts. The freekick was searching for McCallum but the defender on the back post headed it out ahead of him.
Mongoy came off for the Odokonyero on 78 minutes. Somehow Cheadle’s cross missed all of his fellow players down one end before Odokonyero ran on holding possession before having a go himself and shooting wide of the right post on the counter. McCallum’s corner fell to Crane after Thomas punched it to him but Crane misdirected his volley well wide as it flew across the goal and away for a throw in on the other side of the pitch.
McCallum caused all sorts of problems near the end, running at the Robins defence. His shot was blocked and then Odokonyero was also denied by a brave defender who shielded it with his body. Harry Ottaway neatly back-heeled it on for a forward pass to an onrushing Hector but he was closed down by Tangara who got down to stop it. Hector went down in the box but claims for a penalty were ignored.
Cheadle’s corner was headed out to Hector who was blocked from his attempt and then Cheadle, from well outside the area, curled it high over the bar on the follow up as time was running out for the Robins. And Bognor held possession when required at the end as they secured the win.
Rocks: Tangara, Davies, Crane, Dandy, Cook, Robson (Whyte 45), Flannigan, Robb, Diedrick-Roberts, Leigh (McCallum 70), Mongoy (Odokonyero 78). Subs not used: Mendoza, Bell.