Season ticket-holder Biggs, 30, today pleaded guilty to assault occasioning actual bodily harm over the ambush which left the striker needing stitches, says The Sun.
Biggs ran at full speed at Sharp just seconds after Forest won 3-2 on penalties at the Championship play-off semi-final on Tuesday.
He sent the 36-year-old crashing backwards to the ground at the City Ground with a vicious headbutt - leaving him needing stitches.
Nottingham Magistrates' Court today heard the footie fan had got "carried away in the moment" along with thousands of other fans in the stadium.
And he was jailed for 24 weeks and given a 10-year football banning order over the invasion.
Need a VPN? Or seeking to switch? Then support Tribal Football by clicking here to sign up with our official partners NordVPN. Not only will you receive the best VPN experience, but also great discounts by signing up via Tribal Football. Thanks for your support!