Ian Hutchinson set the fastest speed in Monday's opening Superbike practice session for the Isle of Man TT.
The 11-times winner posted a lap at 129.964mph on his Tyco BMW, marginally faster than Michael Dunlop's quickest speed of 129.497 on a Buildbase BMW.
John McGuinness was third on the leaderboard with 128.871mph.
Yorkshire's Dean Harrison was best of the Superstocks on 128.044mph on his Kawasaki and also topped the Supersport session at 124.461.
McGuinness's Honda team-mate Conor Cummins, New Zealander Bruce Anstey and Michael Rutter made up the top six in the Superbike practice after all registering average lap speeds in excess of 127mph.
Michael Dunlop (126.726) and Lincolnshire's Peter Hickman (125.725), both riding BMWs, completed the top three in the Superstocks.
Harrison's Supersport speed bettered his benchmark from the first practice session held on Saturday night.
Ian Hutchinson (124.156) and Michael Dunlop (124.053) lie second and third in the overall standings for that class.
Ivan Lintin is best of the Lightweight class for Supertwins so far thanks to a lap of 116.773 set on Saturday evening.
John Holden and Andrew Winkle were the fastest sidecar crew on Monday night on 112.055mph.
Practice is scheduled to continue on the Mountain Course on Tuesday evening.