Choi has won twice on the PGA Tour this season

South Korea's KJ Choi climbed into a two-shot lead at the halfway stage of the Barclays Classic in New York.

Choi fired a second-round 66 to reach 12 under, with American Rich Beem at 10 under after a 68.

Overnight leader Rory Sabbatini stayed eight under after a 71 and was joined by Steve Stricker and Geoff Ogilvy.

Ernie Els and Sergio Garcia were locked on six under, while Ian Poulter was the highest-placed Briton on five under after a second-round 67.

World number three Phil Mickelson was also five under, one shot clear of England's Justin Rose, who birdied his last three holes for 68.

"I would've liked to be a little more under par because when KJ gets it going, he's got the ability to keep going," Mickelson said.

Ireland's Open champion Padraig Harrington also shot 68 for three under alongside England's Brian Davis, who leaked three bogeys in his last four holes for a 71.

Choi, who has won twice on the PGA Tour this season, had four birdies, one bogey, an eagle at the par-four seventh and closed with eight straight pars.

Choi is enjoying a breakthrough season thanks to an improved putter with a unique grip, which he paid $49 (�24) for after seeing it advertised on the Golf Channel two years ago.

"There was something about my game, my putting ... something missing," he said.

"I thought it made sense, so I picked up the phone and I ordered it and it came. "It did look ridiculously big."

US Open champion Angel Cabrera (74, 69), England's Luke Donald (68, 75) and Fiji's Vijay Singh (75, 71) all missed the cut.