Glenn Irwin set an unofficial course lap record in posting the fastest speed of the opening Superbike practice session at the North West 200 on Wednesday.

The PBM Ducati rider topped the timesheets with a lap of four minutes 18.553 seconds, 124.895mph.

That speed bettered Peter Hickman’s two-year-old existing benchmark of 124.799 by two tenths of a second but remains unofficial as only laps registered in a race count towards the official record books.

Irwin was fastest for most of the session until Milwaukee BMW rider Davey Todd moved to the summit of the leaderboard with a circuit at 124.243.

The Carrickfergus rider reasserted his authority on his final lap to take provisional pole for the three Superbike races, the first of which will be staged on Thursday evening after the completion of the qualifying sessions earlier in the day.

The 34-year-old has won the last eight editions of the premier big bike class of the meeting and is aiming to equal and surpass the record of nine Superbike wins at the event achieved by Michael Rutter and the late Joey Dunlop.

Todd was quickest of the Superstocks with a speed of 123.752, with Dean Harrison next (123.476), marginally ahead of Michael Dunlop (122.416).

Richard Cooper was fastest in the Supersports at 117.767mph, just 0.8 seconds ahead of second-placed Todd on 117.418.

The Supertwins run was halted because of a red flag, with Jeremy McWilliams recording the best speed of a truncated session at 106.862mph.