كتب : Hatem Maher
Australian striker Mark Viduka put the Magpies ahead after six minutes with a low shot past Fulham keeper Kasey Keller.
Michael Owen sealed the victory seven minutes from time when he headed home Geremi's free-kick.
The win will come as a major boost to Keegan, who suffered a miserable run of results since his appointment in December following the sacking of Sam Allardyce.
Newcastle eased their relegation fears as they lie in 13th place of the league table with 32 points while Fulham lie second from bottom on 23 points.