SHANGHAI, October 25, 2013 (AFP) - The 23-year-old from Illinois shot a one-under-par 71 after his sparkling 65 on Thursday to maintain a four-shot lead on a second day of cold winds gusting up to 35 mph across the wide open Lake Malaren layout.
"Yeah definitely surprised (to be four clear). But I have been playing well and really hitting it well," Guthrie said after his round.
Guthrie's putter had been red hot on day one of the $7 million European Tour event as he took just 19 strokes on the greens but it, like the weather, had cooled considerably on Friday.
"It was another difficult day. Anything in the red was a good score today," he added. "Had a couple of bogeys. Always disappointing to bogey the last. But I made some good swings."
Rory McIlroy, the former world number one who was runner-up at the event last year, found the brutal winds tough but hung on to the leaders' coat-tails with a level-par 72 to remain at one-under for the tournament and in a share of 12th place.
"Testing day again," said McIlroy, who again showed signs of being back to near his best with an excellent display of driving from the tee.
"A couple of holes where I didn't get it up and down like I should have. But I still haven't done myself much damage," added the 24-year-old from Northern Ireland.
"Hopefully the weather clears up a bit by the weekend and we can start making more birdies."
Behind Guthrie, no fewer than six players were tied for second at four-under, including England's Simon Dyson whose second successive round of 70 could have been much better if not for a double-bogey at the final hole.
"I played brilliantly up till then," lamented the Englishman.
Also on four-under were Thailand's Thongchai Jaidee, Argentina's Ricardo Gonzalez, Scottish pair Craig Lee and Scott Jamieson and England's Paul Casey.
"I have putted nicely for two days which has been really key," said Casey, who has dropped out of the world's top 100 recently, despite winning the Irish Open this season.
"You're not going to hit a huge amount of greens out there so you've got to be able to putt," he added, after a second successive round of two-under par 70.
Casey said his goal over the last four weeks of the European Tour season was to win at least one tournament and climb back into the world's top 50, which would get him into big events in 2014 including the Masters.
"Top 50 would be the best golf Christmas present I could have," Casey said. "But nobody's going to give me it. I've got to go and get it myself."
Northern Irishman Graeme McDowell, who is second in the European Tour Race to Dubai standings and harbours ambitions of overtaking leader Henrik Stenson, started the day two under par.
Through 13 holes two birdies and a bogey had moved him up to three-under before the wheels came off.
McDowell bogeyed three of the next four holes to slip to a two-over round of 74 and back to level par for the tournament and in a tie for 19th place.
Stenson, who has been troubled by a wrist strain this week, also carded a 74 to finish at two-over par 146.
Leading scores on Thursday after two rounds of the European Tour's $7 million BMW Masters at Lake Malaren Golf Club, Shanghai (par 72):
136 - Luke Guthrie (USA) 65-71.
140 - Paul Casey (ENG)70-70, Simon Dyson (ENG) 70-70, Ricardo Gonzalez (ARG) 73-67, Craig Lee (SCO) 70-70, Scott Jamieson (SCO) 72-68, Thongchai Jaidee (THA) 70-70.
141 - Rafa Cabrera-Bello (ESP) 73-68.
142 - John Daly (USA) 68-74, Gonzalo Fernandez-Castano (ESP) 71-71, Brett Rumford (AUS) 73-69.
143 - Marcus Fraser (AUS) 73-70, Pablo Larrazabal (ESP) 70-73, Gregory Bourdy (FRA) 70-73, Francesco Molinari (ITA) 72-71, Ian Poulter (ENG) 74 69, Rory McIlroy (NIR) 71-72, Lee Westwood (ENG) 72-71.
144 - Bernd Wiesberger (AUT) 75-69, Padraig Harrington (IRL) 72-72, David Horsey (ENG) 72-72, Maximilian Kieffer (GER) 72-72, Peter Uihlein (USA) 69-75, Graeme McDowell (NIR) 70-74.
Selected:
146 - Henrik Stenson (SWE) 72-74.
151 - Louis Oosthuizen (RSA) 74-77.