Stuart Appleby of Australia during the second round of the US Open at Torrey Pines on Friday. (Reuters)

La Jolla: His left knee could be hurting him, he might be playing his first tournament in two months and he may have started with four bogeys on his first nine holes, but at the midway point of the US Open, there’s only one player in front of Tiger Woods.

Stuart Appleby’s cross country birdie putt at the 18th hole on Friday at Torrey Pines was not only noteworthy for the ground it covered, about 45 feet, but also for the fact that it concluded a one-under par round of 70 and turned out to be worth a one-shot lead over Woods, Rocco Mediate and Robert Karlsson.

Appleby said he wouldn’t exactly be looking over his shoulder at Woods.“He wants to play golf and we want to play golf. I’ll be doing my best to accidentally throw a club towards his sore knee,” Appleby said.“It would be an accident, of course.”

Woods almost made it all look so easy, except for the fact that it wasn’t, but going five under on the front, his back nine holes, looks good in retrospect.Woods climbed over 29 players with his three-under 68, wound up the US Open clock and got it ticking on Tiger time.

Mediate, who birdied the 18th for a 71, and Karlsson, who did the same thing for his 70, helped steady a rocky afternoon for the half of the field that drew the later tee times.

D.J. Trahan, Davis Love III, Lee Westwood and Miguel Angel Jimenez are tied for fifth, two shots behind Appleby. Jimenez’ 66 was the low round of the day, when few resembling anything like that were turning up.

Woods’ opening moment wasn’t so great, a three-putt bogey at his first hole, the 10th, followed by a missed green that led to another bogey at the 12th, an alarming trend of misdirection.

Phil Mickelson shot a 75, Adam Scott had a 73 and both are at four over.Padraig Harrington was in the seventh group off the 10th tee in the morning and shot a four-under 67.

Ernie Els birdied the last two holes to rescue his round, a one-over 72, and stay within reasonable distance of the lead and a possible third US Open title at even par 142.

Woods was asked several questions after his round about the condition of his surgically repaired left knee and felt the subject was fair game.When asked whether a 14th major title is on his way, Tiger said,“People will find out.”