Dean Harrison edged out Michael Dunlop to finish top of the standings after the first Superbike practice at the North West 200.
The Englishman crossed the line in 4:26.413 on his Kawasaki, half a second faster than Dunlop (BMW) in second and 1.637 seconds faster than Alastair Seeley (Ducati) in third.
Harrison's best finish at the North West was his second-placed finish last year, however he's set the pace this time around and is looking good at the top.
The event's most successful rider, Seeley, did have plenty of consolation as he finished fastest in the Supersport practice to start the day, clocking a time of 4:37.073.
The Northern Irishman formed a Yamaha one-two, with Lee Johnston just .182 of a second behind him, while James Hillier on the Kawasaki was third, 1.113 seconds further back.
Seeley's lap averaged 116.55mph, with Johnston hitting 116.47mph behind him.
In the Superstock practice, last year's winner Peter Hickman took top honours with a 4:25.891 lap time as BMWs dominated the final standings.
The top three riders, Hickman, Johnston (+1.437s) and Dunlop (+1.499s) were all aboard BMWs, who appear to have the edge in the class going into Thursday's first race.
And in the Supertwins category it was West Yorkshire's Jamie Coward who led the field with a lap time of 4:57.829 as the Kawasaki riders showed the early pace.
The top-five finishers were all aboard Kawasakis as Coward hit an average lap time of 108.42mph and was followed in by Michael Rutter (+0.2s) and Christian Elkin (+1.102s).
Check out our gallery of the best pics from day one of practice by clicking the main image above!
Belfast Telegraph Digital