Reigning Southern 100 Solo Champion Michael Dunlop has shown his rivals he is determined to defend his title.
During the opening practice session on Monday, he topped the Superbike timings with a speed of 109.573mph.
Next were Ryan Farquhar (107.035), Ian Lougher (106.686) and Guy Martin (106.632).
Ian Lougher was quickest in the 600cc class with a lap of 105.403mph followed by Guy Martin (104.679), Michael Dunlop (104.644) and Conor Cummins (104.201).
Newcomer Tim Reeves with experienced passenger Dan Sayle was fastest in the Sidecars at 94.605mph ahead of Greg Lambert and Dicky Gale (94.466), Wayne Lockey/Kenny Cole (92.637) and Conrad Harrison/Dipash Chauhun (92.445).
Castletown rider Chris Palmer tops the standings in the 125/400cc class with a speed of 93.667mph ahead of Billown débutante Sam Wilson (92.559) and Dave Madsen-Mygdal (90.706).
And in the 250/650cc class - first was Ryan Farquhar at 99.590mph ahead of his young charge Jamie Hamilton (99.278) and Chris Palmer (98.731)
One sidecar session was red flagged due to a two-outfit collision at Ballabeg. A passenger was taken to Nobles Hospital for observation - there are no further details.