Final leaderboard+1 W Simpson (US)+2 G McDowell (NI), M Thompson (US)+3 D Toms (US), P Harrington (Ire), J Peterson (US)+4 E Els (SA)SAN FRANCISCO – Winning his first major title at the U.S. Open on Sunday turned out to be far more difficult than Webb Simpson ever imagined.The 26-year-old American triumphed by a single shot after a grueling afternoon at the Olympic Club and he was indebted to his caddie, Paul Tesori, for making sure he stopped watching the leaderboard early in the final round."I was glad Paul told me that because I’ve been a leaderboard watcher my whole life,” Simpson told reporters after sealing victory at the year’s second major with a two-under-par 68."With what pressure a major brings, I just didn’t think it would do any good to see where I was at. So much can happen during the middle part of the golf course, so I didn’t look again.Simpson began the final round at fog-bound Olympic four strokes off the pace and he teed off in the fourth-last group of the day.Four birdies in five holes around the turn lifted him into contention but he then had to watch on television to see if overnight leaders Jim Furyk and Graeme McDowell could match his one-over total of 281 as they played the final two holes."I just gained so much respect for the guys who have won multiple majors, because it’s so hard to do. The level of pressure is so much greater than a regular event."I don’t know how Tiger (Woods) has won 14 of these things (majors) with that pressure. I couldn’t feel my legs for most of the back nine.”Simpson has surprised even himself by how quickly he has won his first major title.His maiden victory on the PGA Tour came late last year at the Wyndham Championship, in his home state of North Carolina, and he then clinched his second at the Deutsche Bank Championship soon after.