Longford 2-14 Limerick 0-9
Francis McGee and JJ Matthews goaled for Longford early in the second-half to oust Limerick from the championship at Pearse Park.
Just four points separated the sides at the break, but the home side hit a rapid fire 1-2 in the next three minutes to stun Maurice Horan's men.
Sean McCormack finished with eight points for the Leinster side, who eased into Round 2 and put on a terrific display of attacking football.
Limerick finished with 13 men after Michael Reidy and JJ Matthews were sent off in the closing stages, but by then the result was well beyond doubt as Longford picked their visitors apart.
Longford got off to a flying start with two points from McCormack and Matthews, who was making his first senior start for Glen Ryan's men.
But Limerick responded when Eoghan O'Connor kicked his first of three points for the Treaty men.
Another two points from their dangerous inside line of McCormack and Matthews opened Longford's lead out to three points and late in the half McCormack followed a super point from John Keegan to give his side a 0-8 to 0-4 lead at the break.
But the key action of the game took place just after the restart, and once McGee rattled the net in the 37th minute there was no doubt about the victors.
Without a competitive win all season, Longford were not satisfied to cruise to the win and ten minutes later Matthews capped off a splendid move and rattled the net to open out an 11-point lead.
Limerick briefly recovered and Seanie Buckley began to find his groove as his three second-half points kept Limerick’s slim hopes alive.
But Longford continued to impress and McCormack hit his eighth point, before substitute Niall Mulligan kicked two of his own in the last six minutes to catch the eye.
Limerick's miserable night was compounded when Reidy was shown a straight red card for his actions in a fracas, while Riordan joined him on the sidelines after he picked up a second yellow a minute from time.
Longford: D Sheridan; D Brady, B Gilleran, D Reilly; B O'Farrell, P McCormack, S Mulligan; J Keegan, M Brady; B McElvaney, P Barden (0-1), P Foy; F McGee (1-0), S McCormack (0-8, 5f), JJ Matthews (1-2).
Subs: N Mulligan (0-2) for Foy (49), C Smyth for Barden (64), K Diffney for Keegan (65), A Rowan for McGee (66), S Doyle for McElaveney (66).
Limerick: B Scanlan; M O'Riordan, J McCarthy, A Lane; J Riordan, P Browne, P Ranahan; B O'Brien, J Galvin; S Lavin, T Lee, I Corbett (0-1); E O'Connor (0-3, 1f) , S Buckley (0-3, 1f), G Collins (0-1).
Subs: D O'Connor (0-1f) for Lee (h-t), S Lucey for O'Brien (42), M Reidy for Corbett (46), S O'Carroll for Collins (48),
Referee: D Gough (Meath)