US Open 2012: Luke Donald ready to win first major

World number one Luke Donald says he is "ready" to win his first major ahead of the US Open, as it is "missing" from his CV.

Donald, who recently retained the PGA Championship title at Wentworth, has traded the world top spot with Rory McIlroy several times in the last year.

Defending US Open champion McIlroy has been grouped with Donald and Lee Westwood for the tournament, which starts on Thursday in San Francisco.