CHASKA, Minnesota Tiger Woods stood tall in blustery conditions to lead Irishman Padraig Harrington by one shot late in Friday's U.S. PGA Championship second round on the monster, 7,674-yard Hazeltine National layout.
Defending champion Harrington, playing in the same group as Woods, saw his putt circle the cup before it dropped in for a birdie at the ninth that set up an intriguing back-nine duel between the two rivals.
Woods shrugged off a bogey at the first by birdying the sixth and seventh to end the outward half on six-under-par on a difficult day for scoring, with winds of up to 25-mph (40-kph) whipping the flags and firming up the bumpy greens on the longest course to stage a major.
Tied for third place on three-under were Briton Graeme McDowell (through eight holes) and big-hitting Spaniard Alvaro Quiros (six).
In the clubhouse on three-under 141 were twice winner Vijay Singh of Fiji (72), U.S. Open champion Lucas Glover (70) and Australian Brendan Jones (70).
Britain's Ian Poulter carded a 70 to finish on 142 and predicted hard times for the late starters.
"It's going to be brutal this afternoon," said the seven-times European Tour winner. "The greens will dry out ... and they get a little bit bumpy.
"They don't run quite as true as they do first thing in the morning."
Triple major winner Ernie Els showed low scores were possible as he shot a 68 for 143 but said conditions were growing increasingly difficult.
"It's getting really tricky," the big South African said. "Some of the greens are soft and some are firm. It's a bit inconsistent."
Woods is pursuing a fifth PGA crown that would allow him to match the record held jointly by fellow Americans Jack Nicklaus and Walter Hagen.
(Editing by Tony Jimenez)