The Morecambe rider was fastest in the opening practice session with an average lap speed of 121.63mph, pipping New Zealander Bruce Anstey.

Anstey was fastest in the Superstock class ahead of Alistair Seeley from Carrickfergus and Cameron Donald.

Scotland's Keith Amor topped the Supersport timings with McGuinness second and Ryan Farquhar third.

Superbike practice
1. John McGuinness (Honda) 121.63mph
2. Bruce Anstey (Relentless TAS Suzuki) 120.36
3. Guy Martin (Honda) 120.20
4. Michael Rutter (NW200 Ducati) 120.01
5. Steve Player (Yamaha) 119.32
6. Ryan Farquhar (Kawasaki) 118.70

Superstock
1. Bruce Anstey (Suzuki) 119.09
2. Alistair Seeley (Yamaha) 118.83
3. Cameron Donald (Relentless TAS Suzuki)
4. Conor Cummins (Yamaha) 118.27
5. Guy Martin (Honda) 116.83
6. Ian Lougher (Yamaha) 116.52

Supersport
1. Keith Amor (Honda) 116.06
2. John McGuinness (Honda) 116.04
3. Ryan Farquhar (Kawasaki) 116.06
4. Steve Plater (Yamaha) 115.22
5. Alistair Seeley (Yamaha) 114.33
6. Guy Martin (Honda) 113.35

250cc
1. John McGuinness (Honda) 108.39
2. Michael Dunlop (Honda) 107.27
3. Paul Robinson (Honda) 107.07
4. Christian Elkin (Honda) 106.99
5. William Dunlop (Honda) 106.83
6. Paul Owen (Honda) 104.84

125
1.Michael Wilcox (Honda) 101.65
2. David Lemon (Honda) 100.72
3. Mark Curtin (Honda) 99.39
4. Robert Dunlop (Honda) 99.22
5. Chris Palmer (Honda) 99.19
6. Mark Lunney (Honda) 98.69

400
1. Leo Aldersley (Yamaha) 102.34
2. Oliver Linsdell (Yamaha) 101.46
3. Les Shand (Kawasaki) 100.51