Tiger Woods and overnight leader Justin Rose were the centre of attention early on day two of the U.S. Open, but the third member of their group, Jordan Spieth, enjoyed the best start.
Woods, who clawed his way to a one-under 70 in round one, picked up a shot on his second hole, the 11th, to reach two under for the tournament and sit four behind playing partner Rose.
Yet the 15-time major champion was soon joined on that score by Spieth, after the 2015 U.S. Open winner birdied the 10th, 11th and 13th.
Two-time defending champion Brooks Koepka was alongside Woods and Spieth at two under, having played six holes on Friday.
After equalling the lowest first-round score in a U.S. Open at Pebble Beach with an opening-day 65, matching the mark set by Woods in 2000, Rose began his second 18 with four pars to retain the lead.
The Englishman was briefly joined at six under by Aaron Wise, who offset a bogey at the second with back-to-back gains on the fifth and sixth, only to then double-bogey the par-three seventh.
Meanwhile, Chesson Hadley, starting on the back nine, birdied the 10th and 12th to get to five under.
According to Friday's forecast, breezes were again expected to be relatively tame, taking away one of Pebble Beach's main defences and making it a second consecutive day ripe for scoring.
Thirty-nine players were under par after the opening round, the second-most in U.S. Open history, after the 44 who broke par at Erin Hills in 2017.
The likes of Rickie Fowler, Xander Schauffele, Louis Oosthuizen (all five under after round one) and Rory McIlroy (three under) were among the day's later starters.