Illinois, September 19

Red-hot Jason Day extended his lead and continued to dominate the golf world as he stormed five shots clear after the second round of the BMW Championship at Conway Farms Golf Club on Friday.

The Australian world No 3 backed up his opening 61 with an eight-under 63, including a 43-foot eagle putt at the last, to rocket to 18-under 124 in the third of the PGA Tour's four FedExCup play-off events.

"Usually it's hard to back up a big round and shoot a low one again but fortunately for us, we had calmer conditions today," Day told reporters. "I feel like I'm in the zone. I feel very free and I feel like there's no stress... there's obviously stress but I'm enjoying it." Day tied the PGA Tour record low for the opening 36 holes as he built a commanding five-stroke advantage over Americans Brendon Todd and rookie Daniel Berger.

Todd holed out from the fairway for an eagle at the par-five 18th for a 63, while Berger fired a 64 to post a 13-under total of 129.

World No 2 Jordan Spieth, who played with Day for the first two rounds, was a further two shots back after finishing birdie-eagle for a 66, level with fellow American Kevin Na (66). Top-ranked Rory McIlroy was nine strokes off the pace in a tie for ninth after carding a 65.

While plenty of fireworks went off on a day where the scoring average was a touch better than three-under, the biggest roars were reserved for the Day. The in-form 27-year-old, searching for a fourth victory in six starts, will become world No 1 for the first time if he wins this week and he relishes being the player to beat.

Day fell short in his bid for a record-equalling 59 on the first day when he failed to hole out a 44-yard chip shot from the rough, then missed a nine-foot birdie putt. But the disappointment did not last long as he went back out and destroyed the Conway Farms course with seven birdies, an eagle and just one bogey.