Forest sit in 11th spot following the defeat.
The current sequence of victories beats the Shrimpers' previous record of seven straight wins, which was set in 1924.
Brentford moved four points clear of the Iron with a 1-0 win at 15th-placed Oldham Athletic.
Scott Fitzgerald scored the goal which moves his side up to third.
Meanwhile, Colchester United moved up to 13th following a 2-1 win at struggling Blackpool.
Greg Halford opened the scoring, only for Seasiders striker Tommy Wright to level the scores in the first minute of stoppage time.
There was still time though for Halford to net a late winner, which leaves Blackpool sitting 19th.