By Mark Lamport-Stokes OAKMONT, Pennsylvania (Reuters) - Phil Mickelson's chances of becoming just the sixth man to complete the modern grand slam receded when he missed the cut by one shot at the weather-hit U.S. Open on Saturday. Runner-up a record six times in his national championship, Mickelson will turn 47 during next year's U.S. Open at Erin Hills in Wisconsin and history suggests he is on the verge of battling a lost cause. Nobody has won the U.S. Open at such an advanced age, with American Hale Irwin becoming the oldest champion at 45 in 1990.
