Rory McIlroy won the U.S. Open in 2011.
Rory McIlroy won the U.S. Open in 2011. Reuters

The 2012 U.S. Open got underway Thursday morning, with Scott Langley, Steve Lebrun and Beau Hossler teeing off at 10:15 a.m. ET at San Francisco.

You can see a live look at the 2012 U.S. Open leaderboard here.

Bubba Watson is looking to continue his momentum after winning the Masters in April. The tournament was his first ever Major victory.

Tiger Woods is coming off his second PGA Tournament win since 2009, and is looking to win his first U.S. Open in four years. He's won the event three times. It was the last Major Championship that he won.

Despite Woods' recent struggles in Majors, he's still favored to win the tournament. He won the last time he hit the course when he played the Memorial two weeks ago.

Rory McIlroy is the second favorite to win the tournament, followed by Phil Mickelson and Luke Donald.

McIlroy won the event last year, setting several records in the process. He shot a 16-under, and beat second-place Jason Day by eight shots.

However, he's struggled leading up to the U.S. Open. He's missed the cut in his previous three tournaments. McIlroy is currently ranked second in the world, behind Donald.

Mickelson has never won the event, but he's finished second on five separate occasions.