At the halfway point of the 2015 BMW Championship, Jason Day (AUS, -18) has defended his lead from day one in emphatic manner. The leader in the FedExCup rankings goes into the weekend with a five-shot lead. However, the round of the day came from another of the tournament’s many big names: 2010 BMW Champion, Dustin Johnson (USA, -9).

The rain that fell yesterday evening and during the night had left the fairways and greens at Conway Farms Golf Club damp, but the wind had eased off since Thursday. Good conditions for shooting low. “DJ” took full advantage, carding the day’s lowest round of 62 to climb 31 places into a tie for ninth. 2013 FedExCup champion Henrik Stenson (SWE, -8, T12) also made good progress up the leaderboard, as did 2011 BMW Championship winner Justin Rose (ENG, -8, T12).

The leaderboard on day two also saw world number one Rory McIlroy (NIR, -9) make a move in the right direction. The 2012 BMW Championship winner is now tied with Dustin Johnson and Harris English (USA) in ninth place. Despite a bogey-free second round of six under par, McIlroy was still not satisfied with his day’s work: “I feel like I could have been a lot of shots lower than I was. I hit the ball really well from tee to green. It's just been converting the chances I'm giving myself. That's been a problem over the past few weeks.”

McIlroy is not the only player in a high-class field at the BMW Championship who will have to take their chances over the next two rounds. The main reason for this is the fact that Jason Day simply refuses to budge an inch at the top of the leaderboard. The PGA Champion followed an outstanding opening round of 61 with a 63 on Friday. His halfway score of 18 under par after 36 holes is a personal record and ties the all-time-low on the PGA TOUR.

With his length of hitting, the Australian is in a class of his own on the relatively short course at Conway Farms and radiates confidence. The way the number three in the world ended today’s round was indicative of his current form and frame of mind: with a successful putt for eagle from 42 yards.

"I feel like I'm in the zone. You're not really thinking about mistakes, about pushing forward, or about things that happen or could possibly happen You kind of wash all those thoughts out of your head," said Day.

Daniel Berger and Brendon Todd are tied in second place on 13 under par. Should the two Americans end the week there or thereabouts, they would secure their tickets to next week’s TOUR Championship. This would be a great success, particularly for Berger, who is in his first season on the PGA TOUR.

A further two shots back, Kevin Na (USA, -11) will be setting his sights on a second PGA TOUR win, having previously won the Justin Timberlake Shriners Hospitals for Children Open in 2011. Na is tied in fourth place with Jordan Spieth (USA), who kept his hopes well and truly alive with an eagle on the final hole.