Luke Guthrie gathers speed as he extended his lead at the BMW Masters at Lake Malaren in Shanghai, China. Luke Guthrie / Getty Images After a second round of -1 under par 71 Luke was able to push his lead over the field out to four shots, with a tournament total of -8 under par. Luke said it had been another tough day on the course, an under par score was a good effort; “It was another difficult day out there, anything in the red was another good number and I was able to manage one under. I made a few more mistakes out there, made a few bogeys, which was a little disappointing. It's never fun to bogey the last hole, but it's playing tough. I hit a lot of good shots, a lot of things to build on. I made two great swings on 17 and 18 with irons to finish, and build on that going into tomorrow. I was in good form coming here; got a tie for fifth over in Las Vegas on the PGA Tour, and been hitting it really well.” His nearest rivals are at -4 under par, all six of them: Simon Dyson following his first two rounds of -2 under par 70, Thongchai Jaidee, Paul Casey, Craig Lee, Scott Jamieson and Ricardo Gonzales. Craig Lee holed out from 188 yards on the 16th for an Eagle in his round of -2 under par 70, he did not know the ball was in the hole, he had already pulled his putter from the bag; “Just when I was starting to get a bit frustrated about not moving forward, then bang! I hole a four iron straight into the wind from 188 yards. Always helps the scorecard, especially from a birdie on the hole before, so it was great.” Former World Number Ones Lee Westwood and Rory McIlroy are seven shots off the lead on -1 under par, with Race to Dubai leader Henrik Stenson +2 over par after a 74.