People sensed this could be history. So did his buddy and playing partner, Tom Watson. As the applause lengthened, Watson came to a respectful stop on the fairway and let Nicklaus walk onto the green all by himself, making sure the moment belonged entirely to the Golden Bear.
Will Jack ever be back? Or did the man many consider the greatest golfer ever play his last American tournament in the Champion Tour's Bayer Advantage Classic?
He said all week that he would retire after next month's British Open, but also held out the possibility of competing again in the Memorial, the tournament he hosts each year in Dublin, Ohio.
Nevertheless, after shooting a second straight 73 on the Nicklaus Golf Club at LionsGate, the winner of six Masters, five PGAs, four U.S. Opens and three British Opens looked tired.
'I want to end as a golfer, not as a worn-out celebrity. And that's the way I'm ending it, and I don't like that,' he said. 'I want to end it as a golfer, to play my best.'
The gallery was not alone in feeling a nostalgic tug.
'As I walked to the 18th hole, as I hit my tee shot, I thought, `Yeah, this is probably going to be the last tournament round of golf I play here in the United States,'' he said.
The man whose golf has brought so much pleasure to so many millions no longer enjoys the game himself.
When his final round was suspended by rain on Sunday, he was 3 under - and excited. His goal was to shoot 65 - his age.
'I'd like to have people see me play my best, or at least reasonable,' he said. 'But I managed to go out and three-putt, and make bogey, then three-putted the third hole and three-putted the sixth hole and played my way off into oblivion. It's not a whole lot of fun to do that.'
It's not as though he feels he must win every time.
'I don't have to win the golf tournament, but just to play halfway decent so I can enjoy it and they can enjoy seeing part of me that's still there,' he said.
'I think it's very sad watching old boxers getting blown around in the ring and things like that. That's why I'm wanting to quit while I still have the semblance of a golf game.
'I just wish I'd used it. I'm a lot better golfer than I played today, or this week.'
There is no possibility, he said with a laugh, of somehow recapturing that old magic and deciding to return to tournament golf.
'No,' he said. 'I'm going to win the British Open and then retire.'