Heart of Midlothian 0 Hibernian 1
The midfielder scored with a rare header just two minutes into the contest and it proved sufficient against a punchless Hearts team.
The home side were without suspended duo Christophe Berra and Laryea Kingston and striker Roman Bednar was missing through injury. Steve Banks took over the goalkeeping gloves from Scotland number one Craig Gordon, who was down south, talking over his move to the Premier League.
But Banks was picking the ball out of his net after only two minutes as Hibs made a positive start. Kerr, playing in his first Edinburgh derby, beat Banks with a fine downward header from a Steven Fletcher cross.
It was a typically frantic start to an Edinburgh derby with Hearts anxious to get back level but they failed to put any early pressure on Yves Makaba-Makalamby.
But chances were few and far between in a game punctuated by numerous free-kicks.
Rob Jones lost possession midway through the half but Michael Stewart thrashed his effort over the top when he should have done better.
The midfielder, playing against the club he left in the summer, was in the thick of things in the first half and picked up a booking for a wild challenge on Kerr.
Andrew Driver had Hearts' best first-half chance 11 minutes from the break when he darted into the Hibs' area, but dragged his left-foot shot across the face of the goal.
Hibs put themselves under pressure by failing to clear their lines time and again and they found themselves under the cosh late in the first half.
John Collins replaced Clayton Donaldson at half-time with Abdessalam Benjelloun, but it was Hearts who started the second half stronger and Saulius Mikoliunas shot high over the top with Hibs exposed at the back.
Hibs responded immediately when Merouane Zemmama picked out Benjelloun with a superb pass and his fellow Moroccan volleyed narrowly wide.
David Murphy then tried his luck with a 25-yard free-kick but Banks dived low to keep the ball out.
Hearts were getting such stick from their own fans as they failed to hold on to the ball and both Mikoliunas and Ricardas Beniusis went off to a chorus of jeers midway through the second half.
Benjelloun pulled a shot wide as Hibs looked to have the game by the scruff of its neck.
Substitute Michal Pospisil gave Hearts more threat when he came on but the home side did not seriously look like salvaging a draw.