With all the practice sessions having been cancelled due to either fog or rain, the usual qualifying format was shelved in favour of a single 75-minute session that would both set the grid and give riders some practice time.
This began on a very wet track, but was drying throughout.
As the pole fight began to get serious, Nicky Hayden gave Ducati a brief spell on the provisional top spot before being deposed by Dani Pedrosa's Honda.
But when Lorenzo hooked up a lap, the Yamaha team leader blew his rivals away by six tenths of a second.
He then extended that margin to a full second on his next run.
Lorenzo's title rival Marc Marquez was down in fifth at that point having taken a trip through the gravel.
He recovered to second, 0.6s down on Lorenzo, before sliding off track again.
Hayden hung on to third to keep Ducati on the front row.
Pedrosa fell back to fourth, ahead of Valentino Rossi and Hayden's team-mate Andrea Dovizioso.
Alvaro Bautista had been in the top five heading into the final stages, but sidelined his Gresini Honda with a crash and was left in seventh.
The recovering Stefan Bradl took eighth on his return following the fractured ankle he suffered at Sepang two weeks ago.
CRT pacesetter Aleix Espargaro and Pramac Ducati's Yonny Hernandez completed the top 10, as Tech 3 team-mates Cal Crutchlow and Bradley Smith struggled to 11th and 13th, split by Yamaha wildcard Katsuyuki Nakasuga.