Down 1-16 - Monaghan 1-24: Monaghan held some firepower in reserve and their bench exploded into life in the second half to book a place in the All-Ireland SFC quarter-finals for the fourth time in five years, writes Orla Bannon.
That was a scenario that looked unlikely even at half time when it was 1-9 apiece, with Down looking the better team.
Monaghan manager Malachy O'Rourke brought on his shooters when the game opened up and they contributed a seven-point match-winning haul.
Conor McCarthy led the way with 0-4 with Jack McCarron (two) and Owen Duffy also on target to book Monaghan's place in the last eight for the fourth time in five years.
No Monaghan forward scored from play until McCarron in the 46th minute as Monaghan began to stretch clear.
It was 1-11 each after 45 minutes but Monaghan took control with the forwards starting to find room and Down inevitably tired after putting so much effort into the first half.
Monaghan were supposed to hold all the aces having been shocked by Down in the Ulster semi-final a month ago, but their revenge mission stuttered in a stadium where they have never played their best football.
Despite Hughes brothers Darren and Kieran scoring from distance to give them an early lead, they never looked comfortable and instead it was Down who settled quickest.
By the 17th minute they led 0-7 to 0-4 and were by far the better team, their half-forward trio of Kevin McKernan, Conor Maginn and Shay Millar kicking stylish points.
Caolan Mooney, clearly relishing the chance to push his engine on the big pitch, stretched clear for another.
Monaghan were hanging on – Drew Wylie's struggles on the excellent Connaire Harrison an example of the trouble they were in.
For the second time this summer, Harrison bossed the Monaghan fullback and took three points off him before Malachy O'Rourke moved Wylie's younger brother Ryan onto him.
Conor McManus frees kept Monaghan in touch but they still trailed 0-9 to 0-7 when Fintan Kelly, playing as a sweeper, burst through the gap to score a badly needed goal – his third in as many games.
Darren Hughes' pop pass found him in space and despite having a man outside him, had the confidence to blast home from close range after 26 minutes.
Their narrow lead only lasted six minutes before Harrison replied for Down.
Kelly flapped at a long ball into the square – a tactic that worked so well for Down - and it broke to Maginn, who fed it out to Harrison who finished with the side of his foot finish.
After a thoroughly entertaining half, they went in level 1-9 each at the break but Down probably felt they should have been ahead having taken the game to out-of-sorts opposition.
Monaghan brought on Jack McCarthy and Owen Duffy at half time with Conor McCarthy 11 minutes later and it changed the match.
They opened up the Down defence and McManus chipped in with a couple from play to finish with a haul of 10 points.
Harrison continued his one-man wrecking ball on the Down defence and almost added a second goal, but blazed over from close range in the 62nd minute, with Down trailing by five points. Monaghan closed it out to move into the quarter-finals.
Scorers for Down – C Harrison 1-4, J Johnston 0-3 (1f), D O'Hanlon 0-2 (2f), K McKernan 0-2, C Maginn 0-2, C Mooney 0-1, S Millar 0-1, D McKibbin 0-1
Scorers for Monaghan - C McManus 0-10 (8f), F Kelly 1-0, C McCarthy 0-4, K Hughes 0-3 (1f), D Hughes 0-3, J McCarron 0-2, R Wylie 0-1, O Duffy 0-1
DOWN: M Cunningham; N McParland, G McGovern, D O'Hagan; D O'Hanlon, C McGovern, C Mooney; P Turley, N Donnelly; K McKernan, C Maginn, S Millar; S Dornan, C Harrison, R Johnston
Subs: J Johnston for Dornan (48), A Carr for Turley (52), M Poland for Maginn (58), D McKibbin for Millar (58), D O'Hare for Mooney (68), J Murphy for R Johnston (70)
MONAGHAN: R Beggan; K Duffy, D Wylie, R Wylie; C Walshe, F Kelly, K O'Connell; K Hughes, D Hughes; G Doogan, D Malone, S Carey; R McAnespie, D Freeman, C McManus
Subs: J McCarron for Carey (HT), O Duffy for Malone (HT), C McCarthy for Freeman (46), D Ward for Doogan (48),V Corey for Walshe (62), G Doogan for McAnespie (68), D Mone for O'Connell (70)
REFEREE: Maurice Deegan (Laois)