Harrington started his 2011 season with an opening round 65, for a first round lead at the Abu Dhabi HSBC Golf Championship on the European Tour. He was later disqualified before his second round commenced, after a spectator telephoned in and pointed out an incident of his ball moving an exceptionally small distance closer to the hole on the green, while he was replacing his ball marker, during the first round; it had been shown on television. (The incident led to a rules review, and if it were to occur again, would not be a penalty.) He missed the cut at the Masters Tournament and finished tied for 45th at the U.S. Open. In June 2011, he dropped outside the top 50 in the World Rankings for the first time since 1999.