The official existing lap record around the 37.75-mile TT course stands at 135.452mph set by Peter Hickman in the 2018 Senior race.
As practice came to a close for TT 2023 ahead of the first race day on Saturday, Dunlop on his Hawk Racing Honda unofficially set the fastest ever lap of the mountain course with 135.531 mph on his final lap of the Superbike/Superstock session.
Coming into Friday’s running, Hickman stood as the fastest rider of TT 2023 to that point, having posted a 133.7mph effort on Thursday evening from a standing start.
On Friday afternoon, Dunlop set the pace from a standing start in pitlane at 134.270mph, with Hickman second at 133.195mph on his FHO Racing BMW.
Hickman was late away in the Superbike/Superstock session having been left stranded on the course in the Supersport/Supertwins session when his Yamaha bike in the latter class broke down.
This meant he was one of the last to get out on his Supersport bike and was still on his lap when the Superbike/Superstock session got underway.
Dunlop carried on for a flying lap on his second tour on the Superbike and started to light up the timing screens as his sector times suggested he was inside the outright lap record.
Source: Autosport