Derek Sheils set the pace at the Country Crest Skerries 100 on Saturday on the Burrows Engineering/RK Racing Suzuki.
Showers around the 2.9-mile course in north county Dublin during part of the day saw practice officially untimed, but it was Irish Superbike Championship leader Sheils who clocked the fastest time on the GSX-R1000 by one second from local man Michael Sweeney (MJR BMW).
Darryl Tweed slotted into third, 4.2 seconds back, with Mike Brown, Thomas Maxwell and Forest Dunn the top six, although grid positions will be determined based on standings in the Irish championship.
Guy Martin was a surprise entry for the Senior Classic race. The Lincolnshire man was in action at Skerries on Saturday on his BSA machine. Martin won his class at the Tandragee 100 in May, when he finished second overall in the Classic race.
Mullingar’s Derek McGee is absent as he continues on the comeback trail following his crash at the Isle of Man TT in June. McGee, though, completed a test at Kirkistown in Co. Down on Friday and is nearing a return to action.
Andy Farrell and Sweeney led the way in the Supertwin class, while Kevin Fitzpatrick – the man of the meeting at Enniskillen – was fastest in the Supersport session ahead of Sheils and Sweeney.
Ballymoney’s Gary Dunlop is aiming for a third straight win in the Moto3/125GP class on the Joey’s Bar Honda following his victories at Kells and Enniskillen.
Roads close on Sunday at 8am, with the first race at approximately 10am.