The last of the Irishman's three Major wins came at this event 13 years ago but now at 49 years of age and with the European Ryder Cup captaincy at the forefront of his mind, it was fair to say there was no expectation on Harrington in South Carolina.
But in the tough, windy conditions in which he has always thrived, he finished the week at two under for his best Major finish since the 2012 U.S. Open.
And with Phil Mickelson at 14 months his senior lifting the Wanamaker Trophy, Harrington was left dreaming of a fourth win of his own.
"I walk away from this week, there's nothing stopping me in my golf swing," he said. "I swing the club well enough and I hit the golf ball well enough and I hit it far enough to compete.
"Give me the right conditions, as I probably needed the right conditions even back in my own heyday, and I will be competitive, no doubt about it.
"We all dream it can happen and we push for that and it keeps me getting up in the morning, keeps me practising.
"So this does add a bit of confidence that I'm not too far away and, especially like when I won my Majors, a lot of my Major wins came after me seeing some good stuff and being able to build on that, and I do see some good stuff in this week.
"I was much better focus wise, much better over the last couple of weeks. I changed my routine and I got a lot better since then.
"And going forward, I just need to find that one thing on the putting or whatever and I could be as physically good a player as I ever was, but there's a lot more competition these days."
While Harrington insisted he would not be playing on his own Ryder Cup team regardless of his form, playing partner Shane Lowry is very much in the mix to face the United States at Whistling Straits.
The pair are good friends and after both posting rounds of 69 to finish on the same total for the week, it was clear they had enjoyed their afternoon.
Harrington said: "That was probably my most enjoyable round of golf I've had on the golf course in a long time. It's amazing when you play with a friend, it definitely helped both of us relax and just play golf and both of us played really well."
Lowry added: "When Paddy chipped in on 14, I was like, 'oh, Paddy has got a chance here'. I was kind of trying to cheer him on and play my own game but, honestly, playing with Paddy today was one of the best rounds of golf I've ever had. It was so much fun.
"The two of us had that coming off, we're obviously grinding it out to beat each other and trying to do well in the tournament, and it's just... it was one of the best days I've had on the golf course. I played lovely golf again and very happy going into my week off now."