Galway manager Micheál Donoghue praised Carlow following his team's nervy win in Salthill but stressed that the westerners lacked fluency throughout the encounter.
The 2017 All-Ireland champions, who were held to a draw by Carlow during the league, laboured to a six-point win over last year's Joe McDonagh winners, their lead whittled down to three points at various stages during a fraught second half.
Donoghue paid tribute to the visitors' workrate and scoring efficiency, and noted, in reference to his own team, that when a team fails to work as hard as their opponents, they'll inevitably get into bother.
"It was a very tough challenge. We knew coming in it would be very much that, having experienced them in the league," Donoghue told RTÉ Sport after the game.
"They came with a massive workrate and their efficiency was really high. When you don't work as hard as the opposition, you're going to be in trouble."
Galway led by six points at the break but an underwhelming first half display gave way to an even more disconcerting second half performance as the home side failed to kick on after Conor Cooney's goal.
A Chris Nolan goal revived Carlow's chances when they might have floundered and Bonnar's team stuck close to the victors until the last few minutes, when late scores from Conor Whelan, Niall Burke and Jason Flynn hauled Galway over the line.
"We were six or seven up at half-time. We were probably just getting the scores but there was no real fluency in our game," said Donoghue.
"Huge credit to them, they worked really hard. They were very strong on the puckouts, their scoring efficiency was very high.
"There's a lot of learnings. We'll go away and reflect and chat about it over the coming days. But hopefully we can get a bit better for the next day."
Carlow boss Colm Bonnar was proud of his side's response to Cooney's strike at the start of the second half.
"When Galway came out and scored a goal, a lot of people would have thought that Carlow had their day in the sun," he said.
"But we have a very committed bunch of lads.
"They have huge belief in what they are doing and they've trained hard for this occasion."