The teams face a fourth-round replay at Pride Park and both will enter Monday's draw for the last 16. Northampton's Charlie Goode should have been sent off early on but, after a poor decision from the referee, he was handed a reprieve. Jack Marriott was hauled back by Goode as the last man, with the official not even awarding a free kick.
Rooney, captaining a much-changed Derby side, was always going to be the star attraction against the lowest-ranked team left in this year's competition. Fresh from a lung-bursting defensive run, Rooney almost scored directly from a late corner.
Also Friday, Sheffield Wednesday matched its best showing in the FA Cup since 1997 with a 2-1 win over Queens Park Rangers after strikes from Morgan Fox and Sam Winnall settled an all-Championship tie at Loftus Road.
More AP soccer: https://apnews.com/Soccer and https://twitter.com/AP_Sports