Guy Martin led a number of fellow Isle of Man TT stars as the Steam Packet International Southern 100 got underway on the 4.25 mile Billown circuit in the South of the Island.
Having missed out on a long-awaited first TT victory during this year's event, Martin hit the front of the Superbike timesheets in FP1 with a lap of 2mins 21.844secs aboard the Relentless by TAS Suzuki.
He was followed by 2010 winner Ryan Farquhar and Russ Mountford, though the pair were five and six seconds off Martin's pace respectively. Cameron Donald and Ian Lougher completed the top five, ahead of British Superbike racer Dan Kneen.
Martin set the pace again in the second session, with Paul Cranston rising to second position, while Lougher ascended to third and Conor Cummins was up to fifth with a 2mins 27.523secs lap.
In the 600 class, Martin was fastest again, ahead of Farquhar and Kneen aboard the Relentless by TAS Suzuki GSX-R600.
Action continues on Thursday, with Michael Dunlop and William Dunlop joining the ranks.