Koepka will take a one-shot lead over Corey Conners and Viktor Hovland into the final round at Oak Hill, six weeks after enjoying double that advantage following 54 holes of the Masters.
The four-time major winner carded a closing 75 at Augusta National to finish second to Jon Rahm, but looks primed to claim his first major since the 2019 US PGA at Bethpage.
“It would mean a lot,” Koepka said after a second consecutive 66. “I think a major championship would mean a lot to anybody.
“I was just told that I think only Tiger and Jack have won three, so that would be pretty special to be in a list or category with them. Just got to go out and go play good tomorrow.”
Koepka believes he “choked” in the Masters but has pledged it will be a different story at Oak Hill.
Asked what were the main lessons he had learned from Augusta, the former world number one added: “To just never think the way I thought going into the final round. I think that was a big thing for me.
“I won’t do it again the rest of my career. I promise I won’t show up like that tomorrow (Sunday).”
Conners had led the way on seven under par after covering his first 15 holes in two under par, only to find sand off the tee on the 16th and then embed his second shot into the face of the bunker.
“I didn’t make great contact there,” Conners admitted. “The ball was below my feet and didn’t quite adjust for that. Wish I could have that one back.
“It was an unfortunate situation and a poor shot.
“If I could have dropped it on the side closest to the fairway I might have had a better stance there, but it was pretty clear once we took a look that it was going to be closer to the hole and had to drop no closer to the hole.
“I put myself in a difficult spot there, but you’ve just got to follow the rules.”