Jorge Lorenzo denies Hector Barbera Jerez MotoGP practice top spot

The three-time champion has dominated off-track headlines all week, after confirming he will switch to Ducati in 2017, and followed that up on track in Friday's first practice session.

Lorenzo was relatively anonymous during most of the 45-minute session, sitting in fourth place, more than half a second off the pace with five minutes remaining.

However after halving that gap, he went to the top with a time of 1m40.270s with just over two minutes to go.

That was good enough to lead Avintia Ducati rider Hector Barbera by 0.257 seconds.

Barbera shone on his satellite machine, topping the timesheets on several occasions including before Lorenzo's lap to snatch top spot, and his time of 1m40.527s was 0.853s faster than either factory Ducati rider managed.

Valentino Rossi also spent time at the top and finished third, 0.406s off Lorenzo's pace, while Honda's Dani Pedrosa and Marc Marquez were fourth and fifth.

Marquez's bike appeared to suffer a mechanical problem when he attempted a practice start after the chequered flag.

Suzuki duo Maverick Vinales and Aleix Espargaro were next, ahead of Aspar Ducati's Yonny Hernandez and Andrea Dovizioso, the lead factory Ducati in ninth.

Cal Crutchlow completed the top 10, ahead of Andrea Iannone.

Continuing to stand in for the injured Danilo Petrucci, Michele Pirro was 19th for Pramac Ducati, with Jack Miller - returning after missing Austin - 21st and last.

PRACTICE ONE TIMES