Sabbatini - issued apology (Getty Images).

South African Rory Sabbatini has issued an apology for his extraordinary behaviour at the Booz Allen Classic in Maryland on Sunday.

The World Cup golfer, angered by the slow play of partner Ben Crane, walked on ahead at the final two holes and played out of turn rather than waiting. The crowd booed him on the 18th green.

"In an effort to clear the air and begin my preparation for the 2005 US Open, I would like to apologise for the unfortunate incident," said Sabbatini in a statement released by the US Tour,

"I was quite frustrated with the pace of play, something that has become an all too frequent occurrence on golf courses around the world and reacted inappropriately.

"I have spoken to Ben Crane and the PGA Tour on this matter and it is now behind us. Ben and I remain good friends and have already discussed scheduling a practice round together in the near future.

"I look forward to continuing my support of the PGA Tour, the sponsors and most of all the fans and all the charitable good derived as a result of their efforts."