First-half goals from Byrom and O'Toole for the Cobblers saw them poised to record a comfortable victory but the final half-an-hour of the game was a nervous one for the visitors after Brendan Moloney was sent off for a foul in the box with Crawley halving the deficit from the resulting penalty.
But, not only did Northampton withstand the hosts pressure they created further opportunities themselves before a welcome final whistle was blown on yet another excellent win for Chris Wilder's side.
With leaders Plymouth Argyle being held it means only two points now separate Town from the top of League Two, a testament to the work of Wilder and his squad over the troubled times of the past two months.
Speaking to the official NTFC website after the game, Wilder said: "We had to hang on in there when we went down to ten men but football wise we were good tonight and attitude wise we were even better.