The Addicks won 2-1 at King Power Stadium with former Foxes attacker Yann Kermorgant scoring the opener then providing the winner either side of Wood's 69th minute equaliser.
Leicester dominated proceedings at home but could not deny Charlton going ahead when Frenchman Kermorgant finished neatly from about 12 yards.
Thankfully for the Leicester fans, New Zealand international Wood, who has been out for a couple of matches with a knee injury, came up with his eighth goal in seven outings since his January move from West Bromwich Albion when he fired home with just over 20 minutes remaining.
But Charlton completed the smash-and-grab victory in the 78th minute when Kermorgant flicked on for Darren Haynes to score a sublime winner from 20 yards.
Leicester dropped to fifth on the Championship table because of the loss whilst Charlton moved up to 12th.