Sandro Cortese completed a dominant performance in Friday practice but the star of the show on Friday afternoon was unquestionably Harry Stafford, with the British rookie going second fastest in soaking wet conditions.
The Leicester teenager even topped the timesheets at one stage with his 2:00.037 putting him ahead of the likes of Johann Zarco and Luis Salom who were previously setting the pace. Cortese though was demonstrating the wet weather prowess that took him to victory in Australia and took over seconds later on a 1:59.760.
As many riders struggled to improve their times, and several struggling to stay on the tarmac, Cortese continued to fly and lowered the benchmark time to a 1:59.126 at the halfway point, giving him almost a second in hand over the rest of the field.
The top three remained unchanged with Zarco 0.038s behind Stafford while Alberto Moncayo put in a 2:00.559 to beat Salom for fourth. The AndalucÃa Banca Civica rider blotted his copybook late on with a fall at turn one but thankfully returned to the pits unharmed.
Adrian Martin ended the afternoon as the quickest Bankia Aspar rider in sixth ahead of Australian rookie Jack Miller and Frenchman Louis Rossi while Hector Faubel got his Aspar Aprilia as high as ninth before crashing out himself.
Maverick Vinales rounded out the top ten but provided a moment of comedy towards the session when he slid off the track. The 16 year old first attempted to return to the paddock via the service road but proceeded to get lost. Instead, he tried to re-join via an escape road, only to come across a dead end in the form of a tyre barrier. He eventually found his way to the pits but his day's running was over.
While Stafford will get the headlines in the UK, wildcard rider John McPhee also impressed to finish 11th, one place ahead of championship leader Nicolas Terol while Danny Webb ended up in 15th despite crashing 20 minutes in and missing the second half of the session. Danny Kent and Taylor Mackenzie stayed out of trouble in the afternoon although they didn't light up the timing screens, finishing 21st and 33rd respectively.