Now there are advantages to having some degree of anonymity, he says. "A lot of great players just behind me".
Compatriot and former BMW victor Jason Day (10/3) leads the pursuers along with Rickie Fowler (3/1), the pair locked together at 13-under and three back of Leishman.
World number nine Day aced the 189-yard par-three 17th at Conway Farms in Chicago en route to a 6-under-par 65.
Starting the day two back of Leishman, who opened with a nine-under 62, Day bounced back from a sloppy start featuring two bogeys with three birdies in his last four holes on the front side, before picking up an additional three shots on the inward half. Stenson in 2015 also was runner-up in the opening two playoff events.
Phil Mickelson is trying to find his way into the top 30.
Leishman arrived in the Windy City lying seventh on the FedEx Cup and is being projected to move to fourth with victory in the penultimate Play-Off event. With a 70-man field, this is the first playoff event without a cut. Two weeks ago, he held the 54-hole lead along with Justin Thomas before faltering late at the Dell Technologies Championship.
The memory still is fresh.
"Confidence is high and hopefully I can just ride the wave", Leishman told reporters. (Boston) took a day. It stung a bit. "It certainly took a few holes for me to adjust to it and I didn't quite have the stuff". Tomorrow I've got to try not to do that.
Day, however, knows that overcoming Leishman could be a tall order on Sunday.
Day made a hole-in-one at the par-three 17th and Fowler carded a pair of eagles to stay in contention on 13 under.
"Leish is playing spectacular", Day said.
"The 62 was obviously pretty nice but, you know, today was nearly as satisfying going into a Saturday with a lead to play the way I did, gave myself a lot of chances". Otherwise, he knows his big lead can evaporate quickly.
"The biggest thing for me is for him to be able to be comfortable enough to have conversations with me out there, " Day said.