Long before half-time, this Connacht SFC semi-final had developed a distinctly macabre quality. Would Roscommon score before half-time? Would they score at all? How long would it take them to recover from this mauling?

The new stand in McHale Park was supposed to play host to a Fergie O'Donnell-inspired new dawn for the once-proud Rossies. After just 10 minutes, he must have felt like going back to bed. Mayo were 1-3 to no score up, the goal coming from on-fire Aidan Kilcoyne. With a neat symmetry, it was 2-6 to nil after 20 minutes, the second goal a Pat Harte penalty. It rolled smoothly onto 3-8 – teenage sensation Aidan O'Shea doing the honours – before Roscommon finally rose a flag.

Conor Devanney's pointed free brought an ironic cheer from the home crowd. Before the break, a few Roscommon supporters had left for home. It was 3-10 to 0-1 at the interval, 18 points to save you doing the sums. The band caught the mood perfectly by playing Mac the Knife. They, too, must be lovers of irony.

This was a disastrous evening for Roscommon – and probably not worth a whole pile to Mayo either, who must enter the Connacht final without anything resembling a test. "At least New York went four points up early on," muttered one Mayo fan, not sure whether to celebrate or be cautious. But after two lack-lustre seasons, they will probably welcome the boost to morale, however insubstantial.

They dominated every position, every contest, almost every thought from start to finish. Roscommon's inability to compete for – let alone win – their own kick-outs was something to behold. Fergie, the man who put the spine back in Roscommon football with the All Ireland minor title win in 2006, must be wondering why he didn't leave well enough alone rather than tempting fate at senior level.

We could offer in-depth analysis, but you wouldn't take much notice of it. Mayo tried the twin peaks O'Shea and Barry Moran at full-forward. Kilcoyne and O'Shea enjoyed a field day. But it was, a day of countless liberties. The supply in was backs-and-forwards stuff. Mayo attacked as they wished, from where they wished, players on the overlap, wing-backs unburdened by tracking-back markers, even corner-backs feeling sufficiently untroubled to ramble upfield to join the fun.

Any escape from the tyranny of the word count, boss? Must plough on. The new stand looks nice. The pitch was fantastic. The half-time food was more than sufficient. The crowd did its best to maintain a pretence of enthusiasm until midway through the second period, but they weren't met half way.

Roscommon didn't score from play until the 47th minute (a neat effort from midfielder Brian Higgins). By that stage, they had to endure the dispiriting sight of their inspirational 2006 minor captain David Flynn exiting the stage, having suffered at the hands of Alan Dillon and Pat Harte. At least a good few got out to see the hurling between Kilkenny and Galway. Many were worried beforehand they wouldn't. Mayo march on. Kinda style.

Roscommon haven't even the luxury of a manager to shaft, their default setting of much of this decade. There is nowhere convenient to point a finger. The post-mortem will be long and painful. Mayo have to wait another day at least before the know something of their true state of health.

MAYO K O'Malley; D Vaughan, G Cafferkey, K Higgins; P Gardiner (0-2), T Howley, A

Moran (0-1); R McGarrity (0-2), D Heaney; P Harte (1-1, 1-0 penalty), A Dillon (0-6, 0-3 frees), T Mortimer (0-2); A Kilcoyne (1-3, 0-2 45), B Moran, A O'Shea (1-0) Subs T Parsons for Heaney, 53 mins; C Mortimer for Kilcoyne, 64 mins; M Ronaldson (0-1) for Harte, 67 mins; K McLoughlin for Vaughan, 68 mins; BJ Padden for Dillon, 69 mins

ROSCOMMON G Claffey; P Domican, J Nolan, P Kelly; S McDermott, D Flynn, D Casey; M Finneran, B Higgins (0-2); G Cox (0-2), K Mannion, D Shine (0-1 free); C Devaney (0-2, both frees), J Dunning, C McHugh Subs P Gleeson for D Flynn, 41 mins; J McKeague for P Kelly, 44 mins; F Cregg for M Finneran, 46 mins; D O'Gara for C McHugh, 50 mins; P Duignan for J Nolan, 50 mins

Referee B Crowe (Cavan)