The 6-5 favourite after five successive victories over hurdles so far, the Willie Mullins-trained chestnut travelled at the head of the field throughout under Paul Townend.
Honeysuckle galloped in his slipstream until the closing stages, where she was unable to follow as State Man powered on off the bend and pulled away to cross the line four and three-quarter lengths ahead.
"Paul surprised me when he came into the parade ring and I asked him what he was going to do and he said he was going to make it," said Mullins.
"He didn't see much to make it in the race so I said 'OK, do that'. It worked out, the horse is not used to being in front, but he jumped well enough in front and Paul thought he was a bit idle in front as well.
"He did everything right and you couldn't ask any more."
When asked about the improvement in his jumping he added: "A lot of people forget that he won the County Hurdle and you don't win that with sloppy jumping.
"In Punchestown it might have been a slow race and when it was slow he just took his time.
"When he has to be sharp he's well able to jump very quickly. He jumped like a Champion Hurdler, I thought, all the way down the back.
"Paul asked some big questions and he came up every time. I was very happy.
"It's nice to have a horse like him and fingers crossed that he stays right."
Just behind Honeysuckle in third was the winner's stablemate Vauban, and Mullins added: "I was very pleased with how Vauban finished off his race.
"He made a mistake at the first and he was a bit giddy before the race in the parade ring and didn't like all that.
"He's still learning and he'll improve away. It might be next year before he'll be the horse we think he is."