World number two Dustin Johnson conjured up memories of John Daly as he plundered a course record nine-under-par 63 to earn a share of the second-round lead at the rain-hit BMW Championship in Indiana.

Johnson collected two eagles, holing a 15-yard bunker shot at the par-five ninth and sinking a 25-foot putt at the 15th en route to his sizzling score at Crooked Stick in Carmel.

The US Open champion joined fellow American Roberto Castro (65) at 14-under 130, three strokes clear of Englishman Paul Casey (66).

World number one Jason Day (67), FedEx Cup points leader Patrick Reed (70) and Monday's Deutsche Bank Championship winner Rory McIlroy (72) all trail by 10 strokes.

The 70-man BMW Championship is the third of the PGA Tour's four playoff events, with the top 30 on a points list advancing to the season-ending Tour Championship and a shot at a $10 million jackpot.

On the same course that Daly overpowered on the way to victory at the 1991 PGA Championship, fellow long-hitter Johnson found the layout to his liking.

The course measured 7,289 yards when Daly, the longest hitter on tour, won 25 years ago, and it has since been stretched by roughly 300 yards, a distance that presented little problem for Johnson in rain-softened conditions.

"I drove it good and hit a lot of good iron shots but I really rolled the putter nicely," Johnson, who put a new putter in his bag this week, told Golf Channel.

"I played solid, four-under on the front, and just kept going, just one hole at a time, trying to get each shot on the fairway and then on the green."

First round leader Castro, boosted by a couple of early 30-foot birdies, matched his opening 65, but it was not enough to stay alone atop the leaderboard.

But the 31-year-old, who lost a playoff in Charlotte in May, had no complaints about his score or his position as he seeks to post a maiden victory on the PGA Tour.

"It was a good start to the tournament," he said. "They don't give any trophies out after 36 holes so there's a lot of golf left but very pleased with that.

"It's really tough on a 'big boy' golf course to shoot low numbers without making a couple (of long putts) here or there. Mine came early in the round."

Third-placed Casey continued the stellar form that earned him the 54-hole lead at last week's Deutsche Bank Championship.

"Really happy with that today," said the former world number three. "This course I feel it's all about the ball-striking because you've got to hit a lot of fairways in order to hit a lot of greens in regulation.

"And the greens are pretty severe. If you can put it the right side of the flag it makes your week easier."