Kaleem Haitham opened the scoring on 24 minutes, while Scott Jones bagged a second half brace and Callum Overton added a fourth one minute before the end of the 90.
Chichester started the game quickly and a long ball over the top found Jones who had strayed offside.
The opening shot of the game fell for the visitors, but Chi captain Connor Cody got himself into a good position to block the effort on goal.
Chichester won the first corner of the night, and it was played deep to the back post towards Cody who headed over.
Lancing were awarded a free-kick halfway inside the Chichester half on 11 minutes which was crossed to the back post, however, goalkeeper Kieran Magee got his fingers to the ball to push it away from danger.
Gicu Iordache then lined up a set-piece for Chichester four minutes later and forced Lancing shot-stopper Mitchell Bromage into a good save. From the resulting corner, the ball fell to Emmett Dunn, who saw his shot blocked. The Chi players appealed for a handball, but the referee was quick to say no.
The first Chichester goal came after Cody was able to burst through the Lancing midfield and find Iordache. The No10 then picked out Haitham on the left and curled a brilliant effort beyond the keeper and into the far corner.
The visitors thought they’d grabbed a quick equaliser as Mark Goldson had the ball in the net, only to see the flag raised for offside.
Next, Goldson looked to be through on goal for the visitors, but the Chichester defensive line communicated well to step up and let the striker go into an offside position.
Jamie Horncastle struck a ferocious shot towards goal from distance on 38 minutes, which took a deflection and went out for a Chi corner that was defended well by Lancing.
William Berry had a chance two minutes before the break for Lancing as he headed the ball down and wide from a corner.
Jones went close five minutes into the second half, heading over from Ethan Prichard’s cross.
Iordache had another good free-kick opportunity, and again, Bromage was equal to it, this time tipping the ball over.
After heading over earlier in the half, Jones made no mistake on 59 minutes. Prichard played the ball to Iordache and he crossed in a superb delivery to the Chichester No9 who headed across the ‘keeper and into the far side of the goal.
Only two minutes later, Jones got his second and Chi’s third. Magee passed a great ball up the pitch to Dunn who then found Haitham. Haitham looked to break through the defence but was tackled. However, Jones collected the loose ball and found the net.
Jones was then replaced on 67 minutes for Callum Overton.
It didn’t take Overton long to have his first chance after entering the match, but his header went narrowly wide.
Clayton Garner won a corner for Lancing and Magee was called into action making a vital double save to keep Chichester’s clean sheet intact.
Matt Axell was brought down inside the area on 77 minutes, but nothing was given by the referee and play continued.
Just before the full-time whistle, Overton got his goal. A long kick from Magee fell to Lancing captain Liam Hendy, but Overton pressured the defender into a mistake and won the ball back. He then charged towards goal and slotted his effort through the goalkeeper’s legs.
The result sees Chichester City move up to 14th in the league table.
Next up for Chi is an Emirates FA Cup First Round Qualifying game away to Northwood.
Chichester City: Magee, Dunn, Hutchings, Horncastle, Cody, Pashley, Prichard, Madhani, Jones, Iordache, Haitham.
Subs: Axell, Vucaj, Heath, Stone, Overton