Former Hornet Alex Laing opened the scoring for the Lancers on 11 minutes. A corner from a Lancing triallist found Laing who finished well.
Harry Heath then doubled the visitor’s advantage on 33 minutes. The forward beat the offside trap and coolly slotted his effort underneath the onrushing keeper to make it 2-0.
Danny Barker reduced the deficit on 52 minutes. The Horsham new boy ran half the length of the pitch before rifling a shot into the bottom corner.
But an excellent Laing strike made sure of the win for the Lancers with 14 minutes to go.
The Hornets host Brightlingsea Regent in their final pre-season friendly this Saturday. Lancing, meanwhile, entertain Southern Counties East Football League Premier Division side Rusthall FC in the FA Cup extra preliminary round on the same day.
See some pictures by Horsham's photographer John Lines on this page and the ones linked.
1. Lancing FC inflict Horsham FC's second home pre-season defeat in four days - the match in 29 pictures
Pre-season action from Horsham v Lancing Photo: John Lines
2. Lancing FC inflict Horsham FC's second home pre-season defeat in four days - the match in 29 pictures
Pre-season action from Horsham v Lancing Photo: John Lines
3. Lancing FC inflict Horsham FC's second home pre-season defeat in four days - the match in 29 pictures
Pre-season action from Horsham v Lancing Photo: John Lines
4. Lancing FC inflict Horsham FC's second home pre-season defeat in four days - the match in 29 pictures
Pre-season action from Horsham v Lancing Photo: John Lines