Golf /US PGA: The trees, an infinite variety of them, which stand custodian on each and every fairway at Oak Hill Country Club may offer shade from an unrelenting sun for spectators here at the 85th US PGA Championship, but the terrain which they so imposingly marshal is not so forgiving to those seeking to plot a route to glory.

As Ernie Els admitted after stealthily playing his way back into contention in the year's final major, "this golf course really gets you in the head."

Indeed, what happened to the South African on his final hole graphically illustrated the point. For much of the day, Els - last year's British Open champion - had stubbornly refused to be intimidated by the rough lurking on either side of narrow fairways, or by greens that got firmer and faster as the day progressed. Then, on the ninth hole, his last, he capitulated. An approach into a bunker was followed by an average sand shot and then three putts for a double bogey six. Ernie had been bitten by the course, and he wasn't alone.

Still, in a year when the three previous majors produced a first-time winner, Els - shooting a second round 70 for one-over-par 141 - at least ensured that someone who has been there, done that, would have others looking over their shoulders.

"I have a chance," insisted Els. "I like this course, it forces you to shoot certain shots. It's a bit of a mental struggle and also physically very demanding."

In truth, the demands placed on the players have been many, but fair . . . and, while fewer than a handful of players threatened to finish the second round under par, those gathering with intent were aware that fortitude over the weekend, as much as clean ball-striking, was an attribute that would decide their respective fates.

For the Irish players who started out, that prospect was remote for one - Padraig Harrington - and non-existent for the other two - Darren Clarke and Paul McGinley - as they finished early in the day to a projected cut of eight-over-par 148. Harrington, who went around without a single birdie, had a 76 to finish exactly on that mark, but Clarke, after a battling rearguard action gave him a 70, and McGinley, who had a 76, both finished a shot outside and could start to move their focus to next week's NEC Invitational in Akron.

Others to suffer included Davis Love, the leader of the US Tour's money list. As if to prove how fickle golf could be, Love, just days after appearing to play on a different planet to everyone in the International tournament, bogeyed three of his last five holes to join Clarke and McGinley on 149.

And Sergio Garcia, who had started the day as joint-leading European player, floundered to 77, also finishing a shot outside the projected cut.

Out on the course, Tim Herron, as if taking inspiration from the number of first-time winners in majors this year, was hot on the heels of US Masters champion Mike Weir who, two-under after 13 holes of his second round, was a shot ahead of Herron at that juncture.

Mickelson, who had shared the lead overnight, was twice in water and suffered two double-bogeys in the first seven holes of his second round - on the fifth and the seventh - and his actions were proving the wisdom of his refusing to get carried away when leading on Thursday.

More than most players, Mickelson is aware that good starts on a Thursday often lead to miserable failures. This is his 46th attempt to win a major, and, on the previous occasions he led after the first round, the 1995 US Masters and the 1999 US Open, he could not hold on. In the 1996 US PGA in Louisville, he led after the second round but finished tied-eighth.

Meanwhile, Tiger Woods, who has never missed the cut in a major as a professional, a streak of 27, continued to lurk with intent. After an error-ridden opening round of 74, the world's number one, who needs to win this last major of the year if he is not to end the season without a major for the first time since 1998, was level-par for his second round after 11 holes.

Meanwhile, young Australian Aaron Baddeley, joint sixth overnight, was penalised two strokes for missing his tee-off time. Baddeley thought his start time was 7.35am when it was, in fact, five minutes earlier and he was late by 40 seconds.

After a 77 yesterday, he said: "I was walking to the tee when a friend told me. I said 'are you serious?' and then began running. It's one of those things. There's nothing you can do."

One man who could relax as the clubhouse leader after his efforts was Billy Andrade, who only got into the field as an alternate. Andrade, who added a 72 to his opening round 67 for one-under-par 139, remarked, "I feel as if I survived today . . . (now) I like my chances, and I can't wait for the weekend.

"You know, I wasn't in the tournament until Monday afternoon and, now I'm in it, I might as well try to make the best of the situation. As Ben Curtis proved at the British Open, anything is possible and, you know, I like my chances. When I get into this position, I kind of thrive on it. I'm going to go for it, (because) I've got nothing to lose."

His devil-may-care approach may be admirable, but he need look no further than Mickelson's past experiences over the weekend of a major to know that there remains a long road to travel before the final destination is reached.