Browne and Langer both shot a bogey-free round. Clampett had two bogeys, but found a way to make up for that with eight birdies. Browne birdied six holes. Langer, who won here in 2008, eagled the par-four, 418-yard No. 6 and had four birdies.
The trio is just one shot ahead of Steve Pate, Bill Glasson, David Eger, Loren Roberts and Tom Kite.
Fred Couples, the 2010 Toshiba champion, is two shots back, along with eight others.
Langer played with Couples and Hall of Famer Nick Price, the Toshiba defending champion, amid a large gallery.
Langer, Browne and Clampett were grateful and pleased with their scores, considering there is a strong chance play could be cut short because of the threat of rain.
Saturday's tee times have been moved up 21/2 hours and will begin at 8 a.m. because of a high probability of heavy rain and wind. The players expect delays.
"[Friday was] a huge day because you don't know what the future is," Clampett said. "We may be playing a one-round tournament with the weather that's coming in. Then again, we may get three rounds in so who knows. When you are playing 54 holes too, it's really important to get off to a good start. I haven't done that for a while. It's nice to get a good one, a good low one, in."
Clampett said he had fun during his first round. He said he usually doesn't play as well in an opening round.
Afterward, he had his wife, Marianna, sit in during his press conference and thanked her for her support.
"I love it. Absolutely," Clampett said of playing competitive golf again.
Browne certainly enjoyed his round too.
"I really enjoy this golf course," said Browne, 52, a three-time PGA Tour winner who has one win on the Champions Tour. "This is one of everybody's favorites."
Langer, a two-time Masters champion, was methodical, and as he put it, "smart," during his first round.
Langer, 54, has had great success on the Champions Tour with 14 victories. He'll try to add another one Sunday, or before the rain comes.
He likes his chances.
"It's a golf course where everybody can win," Langer said of the Newport Beach Country Club layout, which at 6,584 yards is the shortest of three-round events on the Champions Tour. "You don't have to be long. It helps to be long for the par-fives. Even a medium hitter can do well here or a short hitter."
But the rain will provide more challenges.