Brett Quigley surprised to be leading

Surprise U.S. Open co-leader Brett Quigley announced himself to the golfing world on Thursday, but the American was more concerned with first becoming a household name in his own home.

Quigley, the 33-year-old who had missed the cut on his previous two Open appearances, shot a 5-under-par 65 to head the opening round leaderboard at Olympia Fields alongside Tom Watson.

Five successive missed cuts on the PGA Tour this year and a career record devoid of Tour victories hardly indicated Quigley could compete at one of the toughest majors of the season.

But it was belated inspiration taken from his father, his uncle and former Tour professional Dana Quigley and a close friend -- who dubbed him an underachiever -- which set the scene for his day in the sun.

With his father by his side as caddie three days before Father's Day, Quigley realized it was about time he began fulfilling some potential.

"[I am] an underachiever ... I think I am finally realizing and taking steps to get through it," he told reporters.

"A good friend of mine told me that about a month ago. He said, 'What's wrong with you, you should be winning five times a year, you're a great player.'

"It was a slap in the face. But it's been good -- I've played the last month and while maybe expecting more, I've taken some of the pressure off me.

"I don't know where to start with my Dad. He was in insurance for 32 years but he was fired last winter. He said things would work out for the best, and they have -- we played a lot of golf together [recently] and now he is caddying for me.

"He never had a whole lot of talent, but he has a strong heart and mind and if I could be that strong, I could be pretty good."

Dana Quigley never managed a Tour victory during his time as a professional, but Brett added: "Dana loves the game.

"He shames me into playing when I'm at home [in Florida], and I hope he was watching me today."

Quigley insists his change in attitude can help him sustain his challenge at the second major of the year.

"I'll be thinking about [the expectations] but once I get on the course, I'll be okay," he said.

"I'm just going to try and make a bunch of birdies.

"In the past, I have become caught up with being too precise [at the U.S. Open], but I was watching the Golf Channel last week and they showed some old Opens where guys were hitting bad shots.

"Seeing that freed me up. I said to myself that I don't have to be perfect. In the past my attitude has made me be too hard on myself."

It almost seems to tempt fate to suggest he could be saluting the 18th hole galleries as a contender on Sunday with his Dad by his side on Father's Day.

"It would be fun," he said. "We [argue] every hole ... but we talk to each other as well.

"I like having him on the bag, because it keeps me loose."