Nicolas Colsaerts insisted he was close to finding "peak" form after making an encouraging start to the US Open at Merion.
The big-hitting Belgian started at the 11th and opened with two pars before nailing birdie putts at both the 13th and 14th.
But after dropping a shot at the first, he also bogeyed the third and fifth before responding with morale-boosting threes at seven and eight to get back under the card.
Two pars rounded off a 69 and took him into the clubhouse just two shots behind early leader Phil Mickelson, although Colsaerts is wary of further disruption over the weekend due to the adverse weather.
"I don't think I've really peaked anytime during the season," said the Ryder Cup star, who has missed the cut in his last two starts on the PGA Tour.
"It's not very far off, but when you get to play courses that are pretty demanding anything can happen, just as is proven today, really."
Colsaerts enjoyed playing alongside 2012 Masters champion Bubba Watson and fellow powerhouse Dustin Johnson, adding: "Being paired with two very good players, it feels good to play good on a big stage like this.
"It is cool, especially on big tournaments like this, when you see big names up against you."
Torrential thunderstorms arrived less than two hours into the tournament and caused a three-and-a-half hour suspension in play, and Colsaerts was happy to get his round completed.
"I'm relieved," he added. "We know that we are probably going to finish the second round on Saturday morning. Whatever side of the draw you're on, you're going to have to deal with some issues."