Tiger Woods said he had been "monkeying around" with his Scotty Cameron putter before it helped him to his eight-under 62 at the BMW Championship.

The 14-time major champion made an eagle, seven birdies and a bogey on his way to a share of the lead after the opening round of the third FedEx Cup play-off event.

Woods posted an incredible 29 on his front nine, including birdieing three of his first four holes.

The 42-year-old said his putting was the difference on Thursday, confirming he had been practising with his Scotty Cameron Newport 2 before opting to make the switch.

"I've been monkeying around with it at home and in the backyard throughout the summer, just never felt right, but it feels good," Woods said.

"I know the release point. I know how it swings and my body morphs into a position where it understands where it needs to be to release the putter, because I've hit hundreds of millions of putts with that damn thing.

"I've had it since '99 so I've hit so many putts with it, my body just remembers it.

"When I go away from it, even when I was using the Nike putter, I'd always bring it out and hit putts with it and sometimes it works, but it feels very familiar to me."

Woods shares a one-shot lead with Rory McIlroy, while Xander Schauffele is outright third.