Martin set the quickest opening Superbike lap at 127.925mph on is GSX-R1000 to keep him within striking distance of his main rivals John McGuinness, Bruce Anstey and Michael Rutter.
In the Supersport class, Martin was third on his Tyco Suzuki GSX-R600 with a lap-speed of 122.233mph. His team-mate Josh Brookes continues to steal much of the limelight on his TT debut after a lap of 121.99mph - and the fastest Grandstand Speed-Trap time of 180.5mph keeps him well ahead as top newcomer.
"We have a few changes to make on the Superbike but we are going in the right direction. I've still got to get up to speed a bit but the rear Metzeler on the Superbike was brilliant tonight and the front is really egging me on. It was a good night but we need much the same tomorrow."
"I really enjoyed it tonight and the laps came to me pretty naturally, but that's exactly what we need, is laps, after missing a couple of sessions. The Superbike is spot on and the Metzeler tyres are working really well for me. The Superstock bike needs a bit more work but that's only because I'm not used to riding it, although we are going in the right direction."
Philip Neill - Team Manager:
"After a tough start to the week it was great to have a virtually trouble-free run and a decent bit of weather. Guy got three Superbike laps and two on the Supersport bike and is well within striking distance on both GSX-R machines. Josh just continues to impress and was very relaxed tonight despite all the hype and just cracked on with the job. The times are coming for him but they will slow-up as expected, but he's approaching the event with respect and doing a professional job. More of the same tomorrow night would leave us in decent shape for Saturday's Superbike TT."
John McGuinness [Honda] 129.072mph [17mins:32.338sec]
Bruce Anstey [Honda] 129.143mph [17:31.759]
Michael Rutter [Honda] 128.002mph [17:41.132]
Guy Martin [Suzuki] 127.925mph [17:41.777]
Michael Dunlop [Honda] 127.656mph [17:44.011]
Cameron Donald [Honda] 126.964mph [17:49.811]
Josh Brookes [Tyco Suzuki] 121.99mph
Michael Dunlop 122.670mph
William Dunlop 122.259mph
Guy Martin 122.233mph
Bruce Anstey 122.099mph
Cameron Donald 121.973mph
Gary Johnson 120.609mph