The 15,000 additional tickets made available for the Open Championship at Royal Portrush have sold out just three days after their release.
After the original bank of tickets sold in record time, the R&A extended the capacity to allow 3,750 more spectators on each of the four championship days.
A total of 43,750 fans will descend upon the Co Antrim course each day.
Northern Ireland will stage the event for the first time in 68 years from 18-21 July.
R&A executive director Johnnie Cole-Hamilton said the speed of ticket sales "clearly reflects the desire among fans to be part of this historic occasion."
"We really appreciate the passion and enthusiasm for The Open shown by fans in Northern Ireland and beyond," he added.
The release of the additional tickets on Monday came just hours after Tiger Woods' spectacular Masters victory, with the volume of online traffic causing the sales site for crash for several hours.