The Australian's best afternoon lap of 1min 50.334secs was not only enough for provisional pole, by 0.440secs over Yamaha's Fabien Foret, but also fast enough to break the lap record.
"It's great to be fast from the start of the weekend at last!" said Josh. "That has been my aim all season and here at Monza we were finally able to implement it! It makes a huge difference to be fast from the beginning, as now can concentrate on getting the bike faster and make ground on everybody instead of playing catch-up.
"To break the lap record felt good too! The bike is working really well, but there's still room for improvement," he warned. "In some corners, especially the slow ones, I lose a bit of corner speed as I'm not completely comfortable opening the throttle early enough. We will work on that tomorrow."
Fellow Australians Broc Parkes (Yamaha) and Andrew Pitt (Honda) complete the provisional front row, with home hero Gianluca Nannelli heading row two.
WSS first qualifying - top 10:
1. Brookes (Honda)
2. Foret (Yamaha) +0.440secs
3. Parkes (Yamaha) +0.483secs
4. Pitt (Honda) +0.635secs
5. Nannelli (Honda) +1.027secs
6. Jones (Honda) +1.058secs
7. Rea (Honda) +1.077secs
8. Vizziello (Honda) +1.163secs
9. Veneman (Suzuki) +1.275secs
10. Roccoli (Yamaha) +1.521secs
13. Walker (Kawasaki) +1.780secs
27. Coghlan (Honda) +3.234secs
28. Gowland (Honda) +3.235secs