Rory McIlroy mixed the sublime with the untidy to find himself four shots behind US Ryder Cup skipper Keegan Bradley in the BMW Championship in Denver.

As Shane Lowry paid a heavy price for his mistakes and opened with a three-over 75, McIlroy faced 20 footer for par at the 18th and a 69 when play was suspended due to the threat of lightning.

When play eventually resumed after a three hour and 10 minute delay, he missed his putt a signed for a 70 that left him tied for 10th.

Bradley, who was the last man into the 50-man field for the second playoff event, fired a bogey free six under 66 to lead by a shot from Hideki Matsuyama and by two from Sungjae Im, Alex Noren, Adam Scott and Corey Conners.

McIlroy got off to a slow start at Castle Pines, following a tap-in birdie at the eighth with a bogey at the downhill par three 11th, where he came up short in a bunker and put his recovery through the green.

But he sprang to life at the 12th, hitting a spectacular 172-yard fairway bunker shot to three and a half feet.

Back to one under, he then followed an indifferent wedge at the 13th with an eagle three at the 653-yard 14th, where he brushed in a 21 footer from just off the green.

He had a chance to get within two of the lead at the par three  16th but after hitting a sensational iron shot straight over the pin, he missed the seven footer.

He did well to escape with a par five at the 17th after missing the fairway with his tee shot and his second but then compounded that error by being forced to lay up after driving up the face of a fairway bunker at the 18th.

As for Lowry, who like McIlroy is guaranteed his debut in next week’s 30-man Tour Championship, the Offaly man open with a three-over 75 to lie tied 42nd in the 50-man field.

Level par through eight holes after following an opening birdie four with a bogey at the fourth, Lowry drove out of bounds and double-bogeyed the ninth before dropping further shots at the 10th and 12th to slip to four over.

Birdie fours at the 14th and 17th put a better complexion on his scorecard before he bogeyed the last by finding sand with his tee shot and also his 30 yard pitch from short of the green.

Lowry was project to fall from 11th to 18th in the FedEx Cup standings but Bradley would jump from 50th to fourth with a win.

As for FedEx Cup leader Scottie Scheffler, he shrugged off a stiff back and shot a workmanlike 71 that left him tied for 15th, two shots behind his nearest rival Xander Schauffele.

“Really I woke up just a little sore this morning,” said the world number one, who grabbed his back after his approach to the 17th.

“I had trouble kind of loosening it up. With it being a little bit tight it was hard for me to get through it and I was labouring most of the day to get through the ball. 

“On 17 I was trying to hit a high draw, and that's a shot where I've really got to use a big turn, big motion. Really just felt it a little bit. But other than that, all good.”

Scheffler cannot fall further than second in the standings heading to East Lake but he says he’s got no problem remaining motivated with the only thing in doubt his starting position in Atlanta.

“I don't know,” he said. “I mean, if I view it that way, why would we play the rest of the season? Why would I show up to Sony if -- you know what I mean?

“In my head, not one tournament is more important than another. I think of it this way. When I'm practicing at home, I'm practicing and preparing for the season. 

“At the end of the day, though, the majors I think are always in the back of everyone's minds. But I'm not sitting there in November thinking about a certain shot for Augusta. I'm thinking about having the shots that I need to play good golf for most of the season.

“As far as that goes, no, I definitely don't have any trouble getting motivated to come out here and play a PGA Tour event for sure.”