How quickly things change. Last week I still had Dublin as hot favourites to win the All-Ireland, but after Saturday's second quarter-final you'd have to say that Mayo have a serious chance.
The Dubs and Mayo play in the second All-Ireland semi-final at the end of the month, August 30, and it's setting up to be a fascinating game.
Mayo are strong where Dublin are strong - that's primarily the half-back line, midfield and the half-forwards - so it's going to be a case of irresistible force meets immovable object.
Before they beat Donegal at the weekend, I said that Mayo have improved upfront with the addition of Aidan O'Shea at the edge of the square. I said that they'd improved in midfield thanks to Tom Parsons and Seamus O'Shea.
And I said that they still hadn't sorted out their defensive frailties in the full-back line. They have made great strides in that now, with Barry Moran playing as a sweeper on Saturday and offering great cover and security.
They didn't go gung-ho from all over the field as they did in the Connacht final against Sligo, when they conceded 2-11, and they didn't leave themselves vulnerable to the counter-attack.
This game turned on a spell either side of half-time when Neil McGee picked up an injury and clearly wasn't right by the time Aidan O'Shea got the first goal and then Lee Keegan chipped another when he was obviously going for a point.
That was the winning of it because Donegal's style is suited to being in front and defending a lead. This year they struggled to score, going long spells without raising a flag of either colour, and they were never going to win from seven down.
That said, even though they'll find it hard to rebound, I would be slow to write them off just yet.