Derek Sheils, whose participation was in doubt due to a dispute over his entry, set the Superbike pace during practice for the KDM Cookstown 100 yesterday.
The event is the only road race being staged on the island of Ireland this year due to the Covid-19 pandemic - albeit five months later than planned - with racing taking place today around the 2.1-mile Orritor Circuit under tight protocols.
Sheils took his Roadhouse Macau BMW around the course in one minute, 26.617 seconds, which was 2.156 seconds faster than Thomas Maxwell.
Skerries' Michael Sweeney completed a Republic of Ireland one-two-three on the front row of the grid a tenth of a second behind the Mullingar man.
Making up the second row will be Magherafelt rider Paul Jordan, making his debut for the Burrows Engineering-RK Racing team, with near-neighbour Adam McLean, from Tobermore, 1.1 seconds back in fifth on his McAdoo Kawasaki.
Sheils has won the last six Superbike races around the Cookstown course and will start a hot favourite today in both the Open and feature races.
Today's Supersport race should also be a cracker, with McLean and Jordan, separated by less than a second, joined on the front row by Ballymoney's Darryl Tweed, riding the Stanley Stewart Yamaha, a fifth of a second behind.
Sweeney was fourth fastest alongside Cork rider Mike Browne, making his debut on the Burrows Engineering-RK Racing Yamaha.
The McAdoo Kawasaki duo of McLean and Tweed were first and second fastest in the Supertwin session, separated by a third of a second, while Lightweight Supersport saw the 250GP Honda of Galgorm's Neil Kernohan a tenth of a second faster than the 400cc Kawasaki of Tweed, with Davy Morgan, also 250GP Honda-mounted, making up the front row.
John Leigh Pemberton and Barry Davidson head the Junior and Senior Classic grids, with Vinny Brennan and Michael Gillan heading the Junior and Senior Support classes.
A limited 1,600 road race-starved fans will be looking for a safe and competitive day's racing, with roads closing this morning at 10am ahead of a 12-race programme.
Meanwhile, double British Supersport champion Jack Kennedy has been thrown a lifeline in the British Superbike Championship with the news yesterday that he will join the RAF Regular and Reserve Kawasaki Team for the remainder of the 2020 season.
Dubliner Kennedy started the shortened BSB season with the Santander Salt TAG Yamaha squad but, after their withdrawal from the series to concentrate on the 2021 season following problems with the set-up of their machines, they gave him permission to seek an alternative ride.
RAF Regular and Reserve Team owner Lee Hardy has taken Kennedy onboard to join the team's regular rider Ryan Vickers from next weekend's round at Oulton Park.
Kennedy said: "It will be my first time riding the Kawasaki ZX-10RR come Friday's free practice, so I'll take it step by step and see how I go.
"I'm indebted to RAF Regular and Reserve Kawasaki for taking me onboard and Santander Salt Tag Yamaha for allowing me the opportunity."