Donegal were hot favourites to dispense of a Louth side playing in its first ever All-Ireland quarter-final, but the Leinster finalists went toe-to-toe with Donegal for the first half an hour or so.
Twice Louth came to within a point of Donegal in the first half, but the Ulster champions led 0-11 to 0-8 at half time and saw the game through.
McGuinness cut an agitated, anxious figure early on as Louth traded blows with his team, but he grew more content as the game wore on.
He was particularly happy with the spread of scorers with 11 different players on target.
“The way the modern game is, you need that spread of scores coming from all over the place and we got that today,” he said.
“Defensively we conceded 0-18 and Louth looked threatening and dangerous at times so there are areas we have to look at, but the important thing is to progress. Once you do that you have a chance to sort things out and make them better for the next day.”
Donegal are now where they want to be, back in the All-Ireland semi-final for the first time since 2014, the last year of McGuinness’ first stint in charge.
Now he is in year one of his second spell and has transformed the county again.
Starting at a low base, they won Division Two, won the Ulster title and now are in the last four for the first time in a decade.
“We are extremely happy to be in the semi-final, if we were told that at the start of the year, we’d have taken your arm off, so we are thankful for that.
“We are delighted for the people of Donegal here and abroad who give us massive support all the time.”