Michael Dunlop, a three-time winner of the Isle of Man Southern 100 solo Championship, will clash with Dean Harrison, the winner for the last two years, in two of this evening's opening five races around the 4.25-mile Colas Billown Circuit near Castletown.

Dunlop, who set the outright lap record at 115.707mph in 2017, will ride his Tyco BMW in the seven-lap Ellan Vannin Fuels Senior race and his MD Racing Honda in the Radcliffe Butchers 600cc race, also over seven laps.

Harrison, meanwhile, rides Silicone Engineering Kawasakis in both and is on a high after his first Senior TT victory almost five weeks ago.

Dunlop, 21 times a winner around the Billown Circuit, has been struggling with an injury this season after a testing crash at Kirkistown, which he aggravated in his recent Donegal Rally accident, but you can never rule out the determined 30-year-old Ballymoney man as he looks to get miles under his belt prior to the Ulster Grand Prix next month, having not raced since finishing fourth in the Senior TT.

Harrison, 19 times a winner on the circuit, has raced in the British Superbike Championship at Knockhill to keep in trim, so he may well have an advantage over Dunlop.

In Monday's opening 600cc practice session, Harrison set the pace in the wet, 1.7 seconds faster than Jamie Coward and Dominic Herbertson. Dunlop was down in ninth, two seconds ahead of Michael Sweeney, with Denis Booth, from Kells, 11th.

Newcomer Sam West, local men Michael Evans and Ryan Kneen, plus Coward on his Prez Racing Yamahas, may well give the 'big two' a run for their money in both races, but Coward's best chance of a win may come in the 250/650cc race having set the fastest lap in Monday's wet opening practice, eight seconds clear of Rob Hodson.

Magherafelt's Paul Jordan is a non-starter on the RC Express Dafabet Devitt Racing ER6 Kawasaki following his crash at Anglesey, his ride being taken by Dominic Herbertson.

Sweeney should be in with a shout of a podium on his 650 Kawasaki, as should Banbridge rider Stephen McKnight and Ederney's Paul Gartland.

Rhys Hardisty will be looking to put his 250GP Yamaha in amongst the 650s.

Tim Reeves and John Holden renew rivalries in the six-lap sidecar race, both having lapped in excess of 100mph, while local newcomers Ryan and Callum Crowe are worth watching.

An encouraging number of newcomers are entered for the Southern 100 with 15 solo competitors and seven sidecar crews tackling the circuit.

Roy Harris