Having watched his side come up well short in their bid to secure a fifth-straight top-flight win for the first time in 34 years, Clarke had no complaints.
He said: "That was very unexpected.
"We started so slowly it was incredible, you wouldn't believe it.
"We know Swansea are a fantastic team and they play good football and we knew they would cause us problems, but I did not expect so many problems so early and when you are chasing the game it is going to be difficult.
"We have had a really good season, played really well. We came into the game confident, with more or less the same players and system, but that's football, it happens.
"They had a quick start, they got in front and we left ourselves too much to do to be honest."