'Lucky' ace vaults Day into share of BMW clubhouse lead

Day's tee shot at the 188-yard par-three 17th landed just in front of the green, took a couple of bounces and trickled into the hole, much to the Australian's surprise.

"We were trying to land it 182 (yards) and I kind of pushed it. It was a lucky hole-in-one, I guess," Day told Golf Channel after carding a six-under-par 65 at Conway Farms in Lake Forest, where he won in 2015.

"It's been, I think, 10 years since last time I had a hole-in-one. I've had two eagles and a hole-in-one this week already, so everything's come in bunches."

One of those eagles was a chip-in from 30 feet from beyond the green at the par-five 14th. If the hole-in-one was lucky, the eagle was inch-perfect execution.

"It's very quick down there so I just wanted to get something just landing on the green," he said.

"(I'm) Very pleased with how the last two days went. I can't get too far ahead of myself. Last time I was here I was five shots better (after 36 holes). I've got to somehow try to catch up to my number. That's the main goal."

Fowler also finished with a rush, picking up five strokes in the final six holes for a 64 and joining Day at 13-under 129, while first round leader Marc Leishman was still on the course.

The top three players in the FedExCup standings, Americans Jordan Spieth, Justin Thomas and Dustin Johnson, also had late tee times.

The BMW Championship is the third of four playoff events on the PGA Tour. The top points earner after next week's Tour Championship will receive a $10 million bonus awarded to the season-long FedExCup champion. (Reporting by Andrew Both in Cary, North Carolina; Editing by Christian Radnedge)