THE AFL has addressed a timekeeper error in Friday night's Richmond-Geelong clash at the MCG, insisting the final siren sounded at the correct time.

With 42 seconds left on the clock in a pulsating final quarter, the time displayed on the broadcast failed to restart and almost 10 seconds elapsed before it began counting down again after Richmond won the clearance.

League spokesman Patrick Keane says the timekeepers were aware of the error on the night and put in place a contingency plan.

"The timekeepers have a back-up clock and they watched the main clock until it was back in line with the secondary clock," Keane told AFL.com.au on Monday.

"They caught the elapsed time up at the next stoppage.

"The siren went at the right time."

The ball kicked by Tiger Kane Lambert travelled down to Geelong's backline before Cat Lachie Henderson cleared it back to the wing.

The footy returned to Geelong's backline, with 27 seconds coming off the clock at the next stoppage in play when Henderson was tackled by Richmond's Sam Lloyd.

The clock restarted immediately again at 15 seconds.

"The timekeepers waited the same amount of time that had elapsed off the clock at the previous stoppage in play," Keane said.

Richmond held on to defeat Geelong by three points, with no scores registered following the mistake at the 42-second mark.