SAN DIEGO - If the U.S. Open is really about who can endure the most pain and suffering, Tiger Woods is still the man to beat.

Woods looked awful at times in the first round Thursday at Torrey Pines.

His surgically repaired left knee isn't right.

As much as Woods tried to hide it, he's in pain.

That finally came through at the end of a difficult day for Woods, when he winced in obvious discomfort after ripping his driver at the 18th hole. He hit some terrible shots in his return to tournament golf after eight-and-a-half weeks away, uncharacteristically making a pair of double bogeys and three-putting the final green.

And yet even with all those mistakes, Woods is in the hunt after posting a 1-over-par 72. He was just four shots off the lead when he signed his scorecard.

Woods' score put himself right in the middle of that marquee first-round pairing. Phil Mickelson shot 71 and Adam Scott 73.

Woods showed Mickelson and Scott and the masses that chased after them that he's as vulnerable as he is dangerous.

That's what you came away thinking here.

He could walk away with his third U.S. Open Trophy, or he might not walk away at all. They might have to tote him away in a stretcher. He's not really ready for championship golf, but what makes Woods the game's most dominant force is the strength of his mind. We're seeing that again here this week.

Hey, he won the U.S. Open at Pebble Beach by 15 shots eight years ago.

He might be able to win it here on one leg. He won the Buick Invitational at Torrey Pines in January by eight shots, his fourth straight triumph on this course.

If Woods can continue to endure the pain, if the knee holds up, he'll be a factor, but so much is still uncertain after that first-round showing. Woods isn't limping, but he isn't marching between shots the way he normally does. It's subtle, but he's walking with a slower gait between shots.

This was Woods' first 18-hole round since The Masters. He rode a cart when he played his first practice round at Torrey Pines just eight days ago. He didn't walk more than nine holes in his practice rounds this week. He's not really ready to play a major championship, and yet he might win it anyway.

"It's a little sore," Woods confided afterward.

That's as much as Woods is giving away. If the White House could keep secrets like Woods does, nobody would have heard of Woodward and Bernstein. When he announced he was undergoing knee surgery two days after the Masters, golf was taken by surprise. Nobody even knew the knee hurt.

"I thought he played great," Mickelson said of Woods' play on Thursday. "He drove it well. He hit some great par putts. He had three of the best par putts I've seen. I thought that he fought hard and hit some good shots."

Mickelson let Woods know early that he was coming strong. You saw that when Mickelson showed up in a tight shirt with short sleeves, showing off Mickelson's bulked up biceps.

At the first tee, Woods looked his weakest, pulling his drive so far left, he had no choice but hack back into the fairway. From about 80 yards, with lots of room to a back pin, he hit a dreadful wedge, blowing his third shot over the green. He chipped back to 5 feet and missed the bogey putt.

"To make two double bogeys, three putt (the 18th green) and only be four back, that's a great position to be in," Woods said. "I know I can clean that up tomorrow."

There was little chitchat between Woods and Mickelson during the round. Woods chatted with Scott a few times, but Mickelson always remained at a distance.

Video   Tiger holding up June 12: Despite a terrible start and a knee injury, Tiger Woods is in the hunt after the first round. NBC Sports

The intensity promises to build in today's second round.

The question is whether the pain builds, too. And where it builds, in Woods' knee or in the heads of players seeing him make a move?

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