Monaghan 2-16 Kildare 2-14 (aet)
Christopher McGuinness was the hero for Monaghan with an extra-time goal to put the county through to an All-Ireland quarter-final clash with Dublin next Saturday.
Monaghan's first championship win in Croke Park since 1930 came in dramatic circumstances with McGuinness' cool finish in the 79th minute in front of Hill 16 was the decisive score to edge Monaghan past Kildare.
Emmet Bolton scored two first-half goals for Kildare, who thought they had won the game when Eoghan O'Flaherty pointed in the last minute of normal time.
However a free, won and converted by Conor McManus in the first minute of injury time, levelled the scores at 2-10 to 1-13.
The sides level three times in the first quarter.
Emmet Bolton ghosted forward to score two goals inside five minutes of each other.
Alan Smith had a hand in both goals, first beating Drew Wylie in the air and setting up Bolton who raced clear to bury a left-footed shot across Rory Beggan and into the far corner of the net after 19 minutes.
Five minutes later, Smith did well to keep a ball alive along the goal line and fed Cathal McNally who did just enough to force the unfortunate Fintan Kelly to fumble the ball. Bolton was there again to palm the loose ball into the net for his second goal.
Darren Hughes scored an inspirational point to give Monaghan some hope while Conor McManus and Paul Finlay scored 0-3 each from dead balls in the opening half to reduce Kildare's cushion to 2-5 to 0-8 at the interval.
Bolton picked up a black card for dragging down Stephen Gallogly after 38 minutes which was a huge setback to Kildare.
Monaghan edged closer with scores from McGuinness, Finlay and McManus before Vinny Corey hit the net in the 49th minute.
He gambled on Conor McManus winning a ball on his knees and arrived on his shoulder to receive the pass, beating Padraig O'Neill for pace and drilling the ball past Mark Donnellan from about 20 yards out.
It was nip and tuck until Eamonn O'Callaghan thought he'd won it for Kildare with a point in the last minute of normal time, but Conor McManus won a soft-looking free in the first minute of stoppage time, which he converted himself, to take it to extra-time.
Scorers for Monaghan – C McGuinness 1-3, C McManus 0-5 (5f), P Finlay 0-4 (4f), V Corey 1-0, D Hughes 0-1, F Kelly 0-1, J McCarron 0-1, D Wylie 0-1
Scorers for Kildare – E Bolton 2-1, E O'Flaherty 0-4 (1f), A Smith 0-3, N Kelly 0-1, P O'Neill 0-1, H Lynch 0-1, E Callaghan 0-1, P Fogarty 0-2 (1f, one '45')
MONAGHAN: R Beggan; C Boyle (R Wylie 66), D Wylie, C Walshe; D Mone (G Doogan BC, 89), V Corey, F Kelly; D Clerkin (S Gallogly HT), D Hughes; P McKenna (K O'Connell 56, K Duffy 71), P Finlay (J McCarron 78), T Kerr (G Doogan HT, J McCarron 70); K Hughes, C McManus, C McGuinness
KILDARE: M Donnellan; C Fitzpatrick, H McGrillen, E Bolton (E Doyle BC, 38); O Lyons, F Conway (M Conway 85), K Cribbin (D Hyland 70); T Moolick, P O'Neill; C McNally (T O'Connor 53), H Lynch (G White 40, N Kelly 51), E Callaghan; A Smith, P Brophy (S Hurley 66), E O'Flaherty
REFEREE: David Coldrick (Meath)