The TT weather was up to its usual tricks tonight as the session was brought to a premature end with heavy rain and hail stones on the mountain.
Before that it was the Honda of 15 times TT winner John McGuinness that topped the Superbike times with a lap of 122.838 mph - 1.8 seconds faster than his team mate Keith Amor. Gary Johnson was third fastest with his opening lap of 122.463 mph.
In the Superstock class, it was Bruce Ansty who set the pace with a lap on the Padgetts Honda of 122.752 mph. Second was Northern Ireland's William Dunlop, 120.982 mph, with Gary Johnson once again in the top three with a lap of 120.907 mph.
As most of the leading riders were concentrating on the bigger bikes, it left Luis Carreira on top of the Supersport leader board ahead of local man Dan Kneen.
The next qualifying session will take place on the mountain circuit tomorrow (Tuesday) at 6pm.
