Dustin Johnson's overnight lead held up after a see-saw second round at the weather-disrupted US Open was finally completed in dazzling afternoon sunshine at Oakmont Country Club Saturday. England's former world No. 1 Lee Westwood and Frenchman Gregory Bourdy had turns at the top as they moved one stroke clear but they both fell back as the treacherous Oakmont layout became faster and firmer with danger lurking at every corner. The long-hitting Johnson, who missed a three-foot putt at the final hole to hand last year's US Open to Jordan Spieth, had produced superb form from tee to green to card a one-under-par 69 before play was suspended in fading light Friday. That left him at four-under 136 and by the time the marathon second round concluded at Oakmont, he was one shot in front of PGA Tour rookie Andrew Landry, the surprise first-round leader. Landry, the world No. 624 who is competing in his first US Open, recovered from a poor start to card a 71, finishing a stroke ahead of fellow American Scott Piercy (70), Spaniard Sergio Garcia (70), Ireland's Shane Lowry (70) and Bourdy (67). Bourdy had briefly surged one ahead of the field with back-to-back birdies at 13 and 14 following a stunning eagle two at the 11th, where he holed out from 137 yards, but he tumbled backwards with a bogey at the 16th and a double at the last. Westwood also got to five-under with birdies at the first and the fourth before he faded with a run of five bogeys in six holes round the turn on the way to a 72 and a one-under total. Defending champion Spieth ground out another 72 to finish at four-over but several big names missed the cut, which was set at six-over 146. Among those failing to join the 67 players who qualified for the third round, were world No. 3 Rory McIlroy (71/148), fifth-ranked Rickie Fowler (75/151) and five-times major winner Phil Mickelson (73/147). Third-round play was scheduled to begin at 3 pm ET (1900 GMT).