It’s the race before the race. Registration day for the TD Beach to Beacon, the 10K road race founded by Olympic gold medalist Joan Benoit Samuelson ’79, has long been a nail-biter. Thousands of runners sit poised by their computers for an online registration crush that historically fills in a fraction of the time it takes the fastest among them to complete the actual race.

This year was no exception. When registration opened at 7 a.m. Thursday, 4,000 slots were filled in a record-breaking five minutes. Hopeful participants who weren’t that fast have until midnight March 22 to register for one of the 1,850 bibs remaining through a lottery.

The 15th annual Beach to Beacon race is set for Saturday, August 4, in Cape Elizabeth, Benoit Samuelson’s hometown.