Woods (centre) often winced in pain during his first round
Tiger Woods carded a one-over 72 in his first competitive round for two months following knee surgery on the first day of the 108th US Open at Torrey Pines.
The world number one, chasing a 14th major title, double-bogeyed the 1st and three-putted the 18th to slip one behind playing partner Phil Mickelson.
Australian Adam Scott, the third member of the trio, carded a 73.
"The knee's a bit sore but you've got to deal with it," said Woods, who grimaced in pain from time to time.
It was awesome walking the fairways that I've been walking since I was a kid
The 32-year-old Woods, who has won six tour events at Torrey Pines including the last four, finished second to South African Trevor Immelman in April's Masters before undergoing the third operation on his left knee.
But in front of packed galleries and a 100-strong media circus following the world's top three at Torrey Pines, Woods hooked his first tee shot into the left rough en route to a six before fighting back to one under at the turn.
"You couldn't ask for a worse start than I got off to," he said.
"I said to myself I needed to just be patient, because there's a long way to go. We're all going to make mistakes out there.
"I wanted to get back to even par as quickly as I could and then get it to under."
World number two Mickelson, who lives nearby and grew up playing Torrey Pines, dropped three straight shots on his front nine but fought back to card 71.
"The first eight holes are tough but I was able to hang in there and birdie the two par fives on the back nine and turn it around," said the Californian, who has finished second in four US Opens.
The three-time major champion was revelling in playing his local course and said he enjoyed partnering Woods, despite their reportedly less-than-warm relationship.
"It was awesome walking the fairways that I've been walking since I was a kid," said Mickelson, who opted not to carry a driver because of the fast-running ground.
"The support was great and I'm very proud because it's my home town."
Scott was playing with a broken little finger on his right hand sustained the night Manchester United beat Chelsea in the Champions League final in Moscow.
"A friend slammed my hand in the (car) door," he said. "It doesn't affect my golf swing, so I'm pretty lucky to be playing."
Lee Westwood teed off from the 10th tee about the same time Woods's group were starting their round from the 1st and the Englishman was delighted the focus was elsewhere.
"It was great," Westwood said. "I want to thank the USGA for putting them together. It was a lovely, nice peaceful day out there. I think they should do it more often."