Gary Tilley gave Chatham a half-time lead which was wiped out by Paul Oshin within 90 seconds of the restart.
Ilford were unlucky not to take the lead in the 71st minute, when Warren Mfula hit a post, and even unluckier when Chats went straight down to the other end, Rodrigue N'Diane struck the bar and his fellow-sub Harry Smith headed in the rebound.
Mark Lewis added the clinching third goal seven minutes later.
Folkestone became the fourth six-point team in Ryman South with a 1-0 victory at Sittingbourne. Darren Marsden set up the only goal for Stuart King after 15 minutes.
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