The Swansea manager made seven changes from the side that lost 2-1 to Tottenham last weekend, and those coming into the XI at the KC Stadium helped earn a first away win since the opening day of the season.
There was more than a hint of luck about Swansea's winner as Jonjo Shelvey's 25-yard strike deflected off team-mate Ki Sung-yueng and past a helpless Allan McGregor in the Hull goal.
Swansea had the better of the chances, though, with Shelvey and Bafetimbi Gomis hitting the woodwork and the former was also denied by a smart stop from McGregor.
And Monk was delighted by the showing put in by a number of players that had spent the season on the periphery of the first team.
"I knew that, by making those changes, people would question it, but I was very confident in the group," he said.
"We haven't got the biggest squad but we have quality and everyone's working and knows what their roles are. So I had no problems putting players into those positions because I trust them.
"Some haven't had a lot of game time but they showed their fitness and understanding of what we need and we dug in and got the result.
"We've got such a busy period and to play the same 11 players in that period is suicide. We had two or three niggles in the week, so rather than risk it, we made changes."
One the changes came as something of a surprise as Gomis was preferred as the lone striker to in-form Wilfried Bony - who had scored four times in his previous five league outings.
But Monk stated that the decision was influenced by the fact Bony is due to represent the Ivory Coast at the Africa Cup of Nations, which starts in January.
"We're coming up to a period now where he's [Bony] going to the Africa Cup of Nations and Bafi needs game time too, that was behind my decision," he added.
"I thought Bafi did well today and he could have had a couple of goals.
"He's a very good striker, he needs those minutes and hopefully he'll hit the ground running when Bony goes to the Africa Cup of Nations."
