Like the NASCAR Cup Series, NASCAR's second national division O'Reilly Series has had many close finishes since electronic scoring was implemented in 1993. The current record for closest finish was set on February 17, 2018 during the 2018 PowerShares QQQ 300 at Daytona International Speedway, when Tyler Reddick defeated Elliott Sadler at a recorded margin of 0.0004 seconds, which is the closest finish recorded in any of the top 3 NASCAR series history.
NOTE: All finishes are after 1993, when NASCAR implemented electronic timing.