Jorge Lorenzo flies in second Catalunya Grand Prix practice

In searing temperatures several riders elected to fit soft rubber to their bikes in the final minutes, leading to a flurry of late improvements and a jumbled order in which reigning champion Casey Stoner finished just 10th fastest.

Four minutes from the end Bautista (Gresini Honda) set a new record lap at the Catalan track, but his spell at the top of the charts proved fleeting as Lorenzo - quickest for much of the session when the riders were on the harder option tyre - lowered the benchmark to a 1m42.099s on his Yamaha.

That was comfortably faster than the previous best, a 1m42.413s set by Marco Simoncelli during qualifying for last year's grand prix.

Bautista ended the session second fastest, ahead of Tech 3 Yamaha pair Cal Crutchlow and Andrea Dovizioso, both of whom went out on soft rubber in the final minutes.

The Pramac Ducati of Hector Barbera was a surprise fifth ahead of Yamaha's Ben Spies, who had gone fastest with 13 minutes remaining.

Dani Pedrosa was the fastest works Honda rider in seventh, just under eight tenths down on Lorenzo. LCR Honda's Stefan Bradl and Nicky Hayden's Ducati split the Spaniard and team-mate Stoner.

Karel Abraham's Cardion Ducati finished 11th fastest ahead of Valentino Rossi's works counterpart, the Italian 1.4s off the overall pace and just under five tenths slower than Hayden.

Aspar's Aleix Espargaro was the fastest CRT rider in 13th. As was the case in first practice however the high-speed nature of the Catalunya circuit led to a clear gap between the CRT and prototype bikes, Espargaro finishing 1.2s down on Rossi.

Pos  Rider             Team/Bike                 Time       Gap
 1.  Jorge Lorenzo     Yamaha                    1m42.099s
 2.  Alvaro Bautista   Gresini Honda             1m42.306s  + 0.207s
 3.  Cal Crutchlow     Tech 3 Yamaha             1m42.447s  + 0.348s
 4.  Andrea Dovizioso  Tech 3 Yamaha             1m42.592s  + 0.493s
 5.  Hector Barbera    Pramac Ducati             1m42.639s  + 0.540s
 6.  Ben Spies         Yamaha                    1m42.802s  + 0.703s
 7.  Dani Pedrosa      Honda                     1m42.870s  + 0.771s
 8.  Stefan Bradl      LCR Honda                 1m42.943s  + 0.844s
 9.  Nicky Hayden      Ducati                    1m43.057s  + 0.958s
10.  Casey Stoner      Honda                     1m43.134s  + 1.035s
11.  Karel Abraham     Cardion Ducati            1m43.341s  + 1.242s
12.  Valentino Rossi   Ducati                    1m43.538s  + 1.439s
13.  Aleix Espargaro   Aspar Aprilia             1m44.738s  + 2.639s
14.  Randy de Puniet   Aspar Aprilia             1m44.771s  + 2.672s
15.  Michele Pirro     Gresini FTR-Honda         1m45.631s  + 3.532s
16.  Colin Edwards     Forward Suter-BMW         1m45.868s  + 3.769s
17.  Yonny Hernandez   Avintia FTR-Kawasaki      1m46.450s  + 4.351s
18.  Ivan Silva        Avintia Inmotec-Kawasaki  1m46.500s  + 4.401s
19.  Mattia Pasini     Speed Master Aprilia      1m46.503s  + 4.404s
20.  James Ellison     Paul Bird Aprilia         1m46.836s  + 4.737s
21.  Danilo Petrucci   Ioda-Aprilia              1m47.436s  + 5.337s