Three second-half goals were instrumental in Mayo's 4-7 to 0-8 victory over luckless Leitrim at MacHale Park.
Tonight's winners will host Galway for a place in the provincial final next Wednesday, but before that the main talking points from this game are sure to reverberate for quite some time...
The match was held up for an unacceptable 23 minutes in the second half when Leitrim full back Gary Butler sustained a nasty injury in a collision with his goalkeeper (an incident which led to Mayo's second - and decisive - goal from Diarmuid O'Connor) and there was no ambulance at the venue. Thus, the teams had to leave the pitch and wait for one to arrive before the stricken player was brought to hospital.
At the end of an evenly-contested opening period, the victors had led narrowly thanks to a goal from corner back and Man of the Match Michael Hall, 1-4 to 0-5.
Conor Gaffney got the underdogs up and running with the first point and Donal Wrynn added a second for the visitors before James Durkan opened Mayo's account in the seventh minute.
A converted '45' from Mayo goalkeeper Matthew Flanagan tied the scores up but the favourites registered five wides in the opening twelve minutes (and 13 overall); a Gaffney free propelled the confident visitors back into the lead. Gaffney's third point - again from a free - ensured that the Leitrim lads led by double scores going into the second quarter, 0-4 to 0-2.
Leitrim continued to give as good as they got but were caught by a real sucker punch when Hall found their net against the run of play ten minutes from the break to edge the home team ahead for the first time. But the losers levelled immediately with a Gary Plunkett point from play, 0-5 to 1-2.
Points from Stephen Coen and Darren McHale had Mayo two ahead at the break.
Hall and Adam Gallagher increased the gap upon the restart and Shane Ward's charges suffered a major blow in between when they lost Wrynn to a black card. Gaffney's free was cancelled out by a second successful Flanagan '45' as the hosts retained their four-point cushion.
The match was settled as a contest when O'Connor tapped the ball to the back of the net in the 45th minute after a heavy collision in the Leitrim defence involving full back Butler - 2-7 to 0-6.
There was an initial hold-up while the injured Leitrim player received treatment and, with concern growing, both teams were asked to leave the pitch while an ambulance made its way to the Castlebar venue.
When the action finally resumed, Leitrim seemed to have lost their focus and Matthew Ruane fisted a third Mayo goal before Gallagher blasted their fourth to the roof of the net - 4-7 to 0-7.
Nicholas Moore pulled back a Leitrim point but the stuffing had clearly been knocked out of them by that injury to their team-mate and the night ended in a comfortable Mayo success.
Mayo - M Flanagan (0-2'45); M Hall (1-1), D Kenny, J Stretton; S Regan, S Coen (0-1), P Durcan; D O'Connor (1-0), TJ Byrne; V Roughneen, A Gallagher (1-1), D McHale (0-1); C Burke, B Reape, J Durcan (0-1). Subs: C Loftus for B Reape, M Ruane (1-0) for TJ Byrne, M Plunkett for D McHale, M Lyons for D O'Connor, K Lynch for P Durcan, S Conroy for J Durcan.
Leitrim - B Flynn; J Mitchell, G Butler, K McHugh; O Madden, N Moore (0-1), J De Lacy; D Wrynn (0-1), F McHugh; J Rooney, M Plunkett (0-1), D Farrell; G Plunkett (0-1), D McGovern, C Gaffney (0-4, 3f). Subs: N Brady for D Wrynn (BC), K Cox for D McGovern, M Clancy for G Butler, K Shanley for O Madden, D Daly for D Farrell.
Referee - J Gilmartin.