Diarra’s late equaliser made it 1-1 and took the game to penalties – and keeper Metcalfe made two saves in the penalty shootout to give Adam Murray’s men a 4-2 win.
They now take their place in Monday’s third round draw – alongside fellow Sussex sides Worthing and Horsham – in the last 64 of a competition that ends in a Wembley final.
See pictures by Lydia and Nick Redman from a dramatic afternoon at Meadowbank on this page and the ones linked and get the Borough latest in the Eastbourne Herald every Friday.
13. Dorking Wanderers v Eastbourne Borough in the FA Trophy pictures by Lydia and Nick Redman (24).jpg
Dorking Wanderers v Eastbourne Borough, FA Trophy Photo: Lydia and Nick Redman
14. Dorking Wanderers v Eastbourne Borough in the FA Trophy pictures by Lydia and Nick Redman (15).jpg
Dorking Wanderers v Eastbourne Borough, FA Trophy Photo: Lydia Redman : Lydia and Nick Redman
15. Lydia Redman
Dorking Wanderers v Eastbourne Borough, FA Trophy Photo: Lydia Redman : Lydia and Nick Redman
16. Dorking Wanderers v Eastbourne Borough in the FA Trophy pictures by Lydia and Nick Redman (29).jpg
Dorking Wanderers v Eastbourne Borough, FA Trophy Photo: Lydia Redman : Lydia and Nick Redman