Practice got underway on Monday evening at the Southern 100 on the Isle of Man, where Michael Dunlop was back in action for the first time since 2017.
In tricky conditions with showers around the 4.25-mile course, Dunlop was 10th fastest in the first 1000cc practice session on the Tyco BMW.
Reigning Solo champion Dean Harrison was sixth quickest on the Silicone Engineering Kawasaki.
Michael Evans topped the times on his BMW with a speed of 98.385mph.
Mark Parrett was next on his BMW, with Manxman Ryan Kneen third fastest ahead of Stephen McKnight and Jamie Williams.
Bradford man and Senior TT winner Harrison led the way in the Supersport session after completing four laps, setting his quickest lap in 93.943mph to lead the way from Jamie Coward on the Prez Racing Yamaha.
Dominic Herbertson slotted into third on the 600 Davies Kawasaki.
Dunlop was ninth on his MD Racing Honda ahead of Skerries man Michael Sweeney, who is back in action after earning the ‘Man of the Meeting’ award at the Skerries 100 on Sunday following victory in the Supertwin race and three runner-up finishes in the Open, Supersport and Grand Final events.
Yorkshire's Coward was fastest in the Supertwin session from Rod Hodson and McKnight.
In the Sidecar class, Peter Founds/Jevan Walmsley were quickest ahead of Lee Crawford/Scott Hardie and Tim Reeves/Mark Wilkes.
The action was delayed by around an hour due to a radio communications issue.
Practice will continue on Tuesday evening, with the first races taking place on Wednesday ahead of ‘Championship Day’ on Thursday, when the Solo Championship race tops the bill.
Harrison is aiming to join Joey Dunlop and Guy Martin as the only riders ever to win the prestigious feature race in three consecutive years.