A late Mullinalaghta showing pushed the reigning Longford champions all the way.
Mullinalaghta started the stronger in this contest racing into a three-point lead with points form Cian Mackey, David McGivney and Donal McElligott inside the opening three minutes.
Killoe got their opening score of the contest when Conor Mulligan opened his account for the evening. Mark Hughes followed up with Killoes second score of the evening.
Mullinalaghta kicked the next two scores with Shane Mulligan and Donal McElligot registering a point each before Killoe dominated the following 12 minutes.
The reigning champions kicked seven unanswered scores with a pair of Cian Farrelly two pointers. Efforts from Daniel Mimnagh, Gavin Farrelly and Davin Donnelly leaving Killoe in a six-point lead after 21 minutes, 0-11 to 0-5.
Mullinalaghtas 16 minutes scoring drought came to an end when Ronan McGoldrick kicked a point from play on 25 minutes.
Killoe hit three scores on the bounce with their entire half forward line of Daniel Mimnagh, Ronan McGoldrick and Cian Farrelly all on target as they moved into an eight-point lead approaching half time 0-14 to 0-6.
David McGivney kicked the final score of the half for Mullinalaghta as Killoe took a seven-point lead to the break.
At half-time it was Killoe leading 0-14 to 0-07.
Killoe open eith victory
Mullinalaghta opened the scoring for the second half when Aidan McElligott kicked a point from play.
Killoe replied with points from Cian Mackey and Donal McElligot as they retained their double score lead after 33 minutes, 0-16 to 0-08.
The opening goal of the contest arrived on 43 minutes when James Rogers was disposed by Conor Mulligan, with the Killoe corner forward finding the back of the Mullinalaghta net, as Killoe moved into a 10-point lead, 1-16 to 0-9.
Mullinalaghta got their opening two pointer of the contest on 45 minutes when Cian Mackey raised the orange flag, with Ronan McGoldrick and Jayson Matthews trading scores for both sides as Killoe were still in control.
A late Mullinglaghta comeback commenced on 55 minutes when Cian Mackey got his second two pointer of the contest, with David McGivneys move to full forward proving fruitful as he buried the ball to the back of the Killoe net, leaving four between the sides.
Mullinalaghta were then awarded a penalty on the stroke of full time after David McGivney was brough to ground. Cian Mackey stepped up and made no mistake from the spot as only two points separated the sides heading into injury time.
Mullinalaghta tried to engineer a tow pointer to bring the game level in the dying moments, but Killoe held out as last years Longford Senior Football Champions started their campaign with a win.
Killoe running out two-point winners, 1-19 to 2-14 in Glennon Brother Pearse Park.