Scottie Scheffler upstaged by 18-year-old on day two of The American Express

Scottie Scheffler tied for the lead in round two of The American Express in California but the day belonged to Blades Brown. 

The 18-year-old tore round the Nicklaus Tournament Course on Friday, carding a bogey-free 12-under 60. 

Brown, who raced to this PGA Tour event having played in the Bahamas last week, had a putt from inside 15 feet to shoot 59 but missed on the high side.

Yet it was still a remarkable performance from the teenager, who sits atop the leaderboard alongside the world number one on 17-under par.

Scheffler carded a bogey-free eight-under 64. Si Woo Kim is solo second on 16-under. Rickie Fowler and Wyndham Clark are also inside the top-10. 

"These kids coming out they know they got to come out and make some birdies," Scheffler said of Brown. 

"I think when you're coming out young you don't have as much scar tissue as the guys that are a little bit more seasoned, and you just come out, and if you want to make a name for yourself you got to put up some good scores." 

Brown started on the back nine and came racing out of the blocks by playing his first six holes in eight-under. 

He started on the back nine and put circles on his card at 10, 12, 13, 14, 15 and 16. Brown also made eagle at the 11th. 

Brown ticked off another birdie at the second and, after three more birdies at fourth, fifth and sixth was likely dreaming of breaking Jim Furyk's record. 

Furyk is the only golfer in history to shoot 58 on the PGA Tour (2016 Travelers Championship). 

But it wasn't to be for Brown. He played his final three holes in level par.

He later told reporters he was planning on grabbing some food before taking a well-earned nap. 

This was his sixth day in a row playing tournament golf. 

"I just really like this golf course," he said. "There's something about the Nicklaus Course that I just really like. 

"Like, it's so money. It's so pure. Everything is just perfectly well kept. I love playing with no wind. So when you put all those things together it's fun."

Brown said he was nervous as he stood over a putt to break 60. 

"I saw my spot just a little before the hole," he said. "I got a great read off David Ford. He dripped it in there and it went right dead center. 

"So I was thinking, okay, maybe just a little outside right edge. Unfortunately, it didn't break, but it's all right. I'm not worried about it."