A Dan Simmonds hat-trick and late goals from Callum Overton and Jack Parkinson condemned Chi to their first home defeat of the season in this Boxing Day derby.
The prolific Simmonds is on a hot streak and his opener for the visitors in only the fifth minute left the home side shellshocked. Pagham’s No9 cruised past Ellis Martin and gave Ant Ender, who had saved from Overton moments earlier, no chance with a nice finish.
Martin might have redeemed himself two minutes later with a free-kick on the edge of the area that certainly made James Binfield work. Dan Hegarty got on the end of the resultant corner after Binfield palmed the ball away but didn’t get a good connection.
Then in the ninth minute Ruben French whipped a cross in after good work from Scott Murfin that was inches away from strike partner Scott Jones.
Chi spurned another free-kick before a timely tackle from French cut out a dangerous cross. Luke Killner tried his luck on 27 minutes but his shot drifted away.
A minute later Chi skipper Jack Lee picked up a booking that will see him miss the fourth-round FA Vase game on January 6 against Horley Town.
And on the half-hour mark Simmonds, brimming with confidence at the moment, doubled the lead with a low drive into the bottom left hand corner for his 23rd goal in all competitions so far.
Sixty seconds later Simmonds was played in again but Ender did just enough with this skewed clearance to snuff out the danger.
At the other end Binfield was called on to make a second save just before the break gathering an effort from French under the bar.
A lacklustre home side just couldn’t get going and other chances came and went for Simmonds and Lloyd Rowlatt as Pagham pressed.
Overton continued to cause trouble as well and Chi were lucky to get to the interval only two goals down thanks to an impressive double save from Ender – before both Overton and Simmonds went close when City struggled to clear their lines.
Chi boss Miles Rutherford rang the changes at half-time and brought on Kaleem Haitham and Tafadzwa Kanjanda for Martin and Killner.
Both players have made an impact off the bench at different times this season but it was Pagham who forged the first opportunities in the second 45.
Rowlatt wasn’t far off barely a minute in and only a brave block from Lee denied the Lions midfielder after a decent run.
Kanjanda next broke through for Chi and picked out Haitham but he was unable to find Jones after his marker slipped. Then in the 59th minute Kanjanda elected to shoot when he might have squared to Murfin and Binfield got something on his effort.
Simmonds’ third, another crisp finish, came on 76 minutes just when it seemed Chi might get back in the match - it completed the forward’s second hat-trick in a week.
Eight minutes later Pagham provider Overton turned finisher and then in time added on Parkinson fired the ball in from close range.
Reflecting on his side’s heaviest loss this year, Chi first team coach Danny Potter said: “The better team won on the day. Pagham worked harder and were quick and strong in attack which hurt us.
“They’ve got the in-form striker in the league playing well and they have quality players around him. We wish them all the best for the rest of the season. We turn our focus now to Lancing in the league and then the Vase.”
Pagham leapfrog their neighbours into third spot in the table with Chi fourth, one point behind.
City are away to Lancing on Saturday (3pm kick off) and Pagham entertain Loxwood.
Chichester: Ender, Martin, Williams, Lee, French, Hegarty, Clack, Pashley, Killner, Murfin, Jones. Subs. (Haitham, Hutchings, Turnbull, Kanjanda, Ahmed)
Pagham: Binfield, Wiggans, Cox, Booker, Wollers, Horncastle, Thurgar, Chick, Simmonds, Rowlatt, Overton. Subs. (Van Driel, Lewis, Bingham, Parkinson, Rolpnh)