Johnson remains one ahead at brutal Oakmont

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