However, Bolton pulled a goal back with 15 minutes of the game remaining and United had to defend doggedly in the final stages to hold onto their one goal advantage.
"It was harder than it should have been, there were a lot of opportunities to finish the game," Ferguson told Sky Sports after the match.
"When that happens, two-goal leads aren't particularly great.
"They scored and then it was back to walls stuff for that last ten minutes, there was a bit of panic.
"Bolton have got that type of play that makes it difficult for anyone and they're a team who will get results because of that.
They could take points off anyone, they're effective. They have a simple way of playing, they are a very committed team and they have one or two nice talents which brings a nice balance to their team.
"They're difficult opponents and we're quite happy to get a result."