Instead almost 8,500 home fans were left on the edge of their seats as Mayo stumbled alarmingly before eventually snatching the two precious points they needed to stay up.
Down, who were scripted to play the part of cannonfodder, saved their best performance of a disastrous league campaign until last.
With their relegation to the second division already set in stone, Eamonn Burns set his Down team up to play counter-attacking football and took a look at some combinations ahead of the Ulster championship.
As things transpired, Down very nearly brought Mayo through the relegation trapdoor with them, and it too late nervesettling scores from veteran Andy Moran and Evan Regan (free) to settle the argument.
“With two minutes left in injurytime there was only two points in it and it could have either way,” mused Burns afterwards.
“I suppose at the end of the day, Mayo’s experience got them over the line.”
That experience was epitomised by substitute Andy Moran who, in the absence of injured stalwarts like Ger Cafferkey, Keith Higgins, Donal Vaughan and Kevin McLoughlin, stepped into the breach and made his ten minutes count.
It was all about the result in the end for Mayo who won their first game on home ground after defeats to Dublin and Kerry, but it was achieved on the back of yet another patchy performance.
“It’s been a challenging campaign, and today was a challenging game in many ways,” admitted Mayo manager Stephen Rochford.
“We did a lot of good things, but we didn’t defend as a team as well as we would have liked. There were some simple, basic errors.
But when we were on the ball, and we looked to create, I thought we looked very, very good.
“We set out at the start of the league saying that we wanted to get six or seven points, make sure we survived, and that’s what we’ve done.”
On a day when Mayo only played in fits and starts, a second successive man of the match display from corner-forward Evan Regan was a big plus.
The UUJ student looked sharp and finished with nine points (including seven frees) while Cillian O’Connor marked his first start of the year by shooting 14 from placed balls.
Despite starting slowly, Down stayed in touch through a combination of Mayo’s stopstart performance, their own perseverance, and the assured freetaking of Donal O’Hare who chipped in with 15.
Mayo’s early work had suggested they were in the mood to cut loose, and they were 05 to 01 up after five minutes with scores arriving quickly and easily from Alan Freeman, Chris Barrett, Aidan O’Shea and Evan Regan (two frees).
But Down’s running game began to cause Mayo some problems, and frees from goalkeeper Michael Cunningham and Donal O’Hare, along with a neat score from Kevin McKernan gave the visitors something to build on.
However, Cillian O’Connor’s confident penalty conversion midway through the first half looked like being a pivotal moment as it nudged Mayo five points ahead.
The floodgates never opened though and Down proceeded to make a mockery of their 10/1 outsiders’ tag by rattling off six points during the second quarter to make a game of it.
By half-time Mayo led by just 1-9 to 0-10, and the atmosphere around the ground was noticeably flat as Down proved stubborn and awkward opponents.
Stephen Rochford reorganised his troops at the interval and a strong third quarter saw Mayo tag on seven points during an impressive phase to surge ahead by 116 to 012.
At that stage the game looked over as a contest but Down rallied impressively and hit 13 down the home stretch.
The goal was brilliantly finished to the net by Donal O’Hare after David Clarke had saved Seán Dornan’s initial effort.
Incredibly, that left Mayo clinging to a one point lead on 67 minutes and they needed Andy Moran and Evan Regan (free) to guide them to safety.
There’s never a dull moment with Mayo.
D Clarke; B Harrison, K Keane, C Barrett (0-1); L Keegan, C Boyle, S Nally; T Parsons, S O’Shea; C O’Shea, A O’Shea (0-1), J Doherty (0-1); A Freeman (0-2), E Regan (0-9, 0-7 frees), C O’Connor (1-4, 1-0 pen, 0-4 frees). Subs: P Durcan for Barrett (28 mins), A Dillon for Freeman (58 mins), B Moran for S O’Shea (58 mins), C Carolan for C O’Shea (63 mins), A Moran (0-1) for O’Connor (65 mins).
M Cunningham (0-2, 0-2 frees); D O’Hagan, G Collins, G McGovern; D McKibbon (0-1), A Carr, D O’Hanlon (0-1); P Turley (0-1), H Brown; M Poland (0-1), R Mallon (0-1), K McKernan (0-1); C McGovern, S Dornan (0-2), D O’Hare (1-5, 0-5 frees).
P Devlin (0-1) for Mallon (41 mins), C Maginn for Brown (44 mins), D Turley for O’Hanlon (57 mins), B O’Hagan for Poland (63 mins), J Murphy for Carr (70 mins).
J McQuillan (Cavan).