The 2011 U.S. Open is underway, and the world's greatest golfers have trekked down to Besthesda, Maryland in search of a victory at one of the PGA's biggest events.

Defending champion Graeme McDowell did well in his first round at Congressional Country Club, shooting a respectable 1-under for the day. The northern-Ireland native is hoping to become the first European player to repeat as champion since Scotsman Willie Anderson's three-peat from 1903-1905.

2009 PGA Championship winner Y.E. Yang currently sits at the top of the leaderboard, having shot a first-round 3-under. Yang's successful day was the result of some late rallying, as the South Korean closed his last four holes with two birdies.

Local favorite Phil Mickelson, 41, was perhaps the most publicized player coming into this week's action at Congressional Country Club. With old rival Tiger Woods sitting the tournament out due to injury, many speculated that this may be ‘Lefty's best shot to win his first U.S. Open title. However, the Arizona-native is off to an inauspicious start, having kicked off his round with a double-bogey on the par-3 10th hole to dig himself into a early deficit. As of this moment, Mickelson is plus-2 through nine holes.

Coverage of the day's first round begins on NBC at 10 am ET. As the event rolls on ESPN will pick-up the coverage at 3 pm, with NBC resuming coverage from 5 pm to 7 pm.