By Mark Lamport-Stokes OAKMONT, Pennsylvania (Reuters) - Dustin Johnson's overnight lead held up after a see-saw second round at the weather-disrupted U.S. Open was finally completed in dazzling afternoon sunshine at Oakmont Country Club on Saturday. England's former world number one 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. The long-hitting Johnson, who missed a three-foot putt at the final hole to hand last year's U.S. 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 on Friday. More...