Darren Carter's spot-kick equaliser was disputed by Mansfield but it stretched Town's unbeaten run to six games in front of 5,129 at Sixfields.
A draw for Exeter City at Newport County on Sunday kept them three points above the Cobblers but no side in the bottom half of League Two will feel safe just yet.
Promotion chasing Rochdale are the visitors to Sixfields on Tuesday night and Northampton manager Chris Wilder does feel his side will have to improve on their Mansfield showing.
"We know we have to play more than we did today," was his verdict after the match.
"Sometimes we moved the ball quickly and we got into good areas and then there were other times when we took too many touches."
Wilder has been linked with a loan move for Ipswich Town striker Jack Marriott next season should he keep his men in the Football League.