If it's either the 5th or 17th greens (which I expect it would be), most of the slope is right before the cup. If you therefore hit at around 70-75% power (as it seems you've done PMB), you'll be racing by the cup as soon as your ball reaches that slope with too much pace.
You're looking at a trickler down the hill if you want to lag it in; think of 2nd at Oakmont and play it in exactly the same way to get close.
A large part of putting comes down to knowing exactly where the slopes are on a green and how it'll affect your ball. The bottom of the hill on 11 at St Andies is a great example on a legend tourn speed green; you think you need to smash it up there to get it close but in reality it requires a similar pace to a neutral speed putt (around 76-77% after slope) due to the downslope at the top of the crest of the hill.